@selector() in Swift?

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I'm trying to create an NSTimer in Swift but I'm having some trouble.

NSTimer(timeInterval: 1, target: self, selector: test(), userInfo: nil, repeats: true)

test() is a function in the same class.

---

I get an error in the editor:

Could not find an overload for 'init' that accepts the supplied
arguments

When I change selector: test() to selector: nil the error disappears.

I've tried:

• selector: test()


• selector: test


• selector: Selector(test())

But nothing works and I can't find a solution in the references.

swift selector nstimer

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edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

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  selector: test() would call test and pass it's return value to the selector argument.
  – Michael Dorst
  Jun 10 '14 at 4:47
  

  
  
  
  

add a comment | 

up vote
601
down vote

favorite

141

I'm trying to create an NSTimer in Swift but I'm having some trouble.

NSTimer(timeInterval: 1, target: self, selector: test(), userInfo: nil, repeats: true)

test() is a function in the same class.

---

I get an error in the editor:

Could not find an overload for 'init' that accepts the supplied
arguments

When I change selector: test() to selector: nil the error disappears.

I've tried:

• selector: test()


• selector: test


• selector: Selector(test())

But nothing works and I can't find a solution in the references.

swift selector nstimer

share|improve this question

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  selector: test() would call test and pass it's return value to the selector argument.
  – Michael Dorst
  Jun 10 '14 at 4:47
  

  
  
  
  

add a comment | 

up vote
601
down vote

favorite

141

up vote
601
down vote

favorite

141

141

I'm trying to create an NSTimer in Swift but I'm having some trouble.

NSTimer(timeInterval: 1, target: self, selector: test(), userInfo: nil, repeats: true)

test() is a function in the same class.

---

I get an error in the editor:

Could not find an overload for 'init' that accepts the supplied
arguments

When I change selector: test() to selector: nil the error disappears.

I've tried:

• selector: test()


• selector: test


• selector: Selector(test())

But nothing works and I can't find a solution in the references.

swift selector nstimer

share|improve this question

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

I'm trying to create an NSTimer in Swift but I'm having some trouble.

NSTimer(timeInterval: 1, target: self, selector: test(), userInfo: nil, repeats: true)

test() is a function in the same class.

---

I get an error in the editor:

Could not find an overload for 'init' that accepts the supplied
arguments

When I change selector: test() to selector: nil the error disappears.

I've tried:

• selector: test()


• selector: test


• selector: Selector(test())

But nothing works and I can't find a solution in the references.

swift selector nstimer

swift selector nstimer

share|improve this question

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

share|improve this question

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

share|improve this question

share|improve this question

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

edited May 11 '16 at 9:06

Mihriban Minaz

2,64222648

2,64222648

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

asked Jun 3 '14 at 5:21

Arbitur

20.9k1967100

20.9k1967100

• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  selector: test() would call test and pass it's return value to the selector argument.
  – Michael Dorst
  Jun 10 '14 at 4:47
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  selector: test() would call test and pass it's return value to the selector argument.
  – Michael Dorst
  Jun 10 '14 at 4:47
  

  
  
  
  

11

11

selector: test() would call test and pass it's return value to the selector argument.
– Michael Dorst
Jun 10 '14 at 4:47

selector: test() would call test and pass it's return value to the selector argument.
– Michael Dorst
Jun 10 '14 at 4:47

add a comment | 

22 Answers
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accepted

Swift itself doesn't use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.)

But there are still a number of important ObjC-based APIs that use selectors, including timers and the target/action pattern. Swift provides the Selector type for working with these. (Swift automatically uses this in place of ObjC's SEL type.)

In Swift 2.2 (Xcode 7.3) and later (including Swift 3 / Xcode 8 and Swift 4 / Xcode 9):

You can construct a Selector from a Swift function type using the #selector expression.

let timer = Timer(timeInterval: 1, target: object,

                  selector: #selector(MyClass.test),

                  userInfo: nil, repeats: false)

button.addTarget(object, action: #selector(MyClass.buttonTapped),

                 for: .touchUpInside)

view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),

             with: button, with: otherButton)

The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pairs that actually exist and are eligible for use as selectors (see "Selector availability" below). You're also free to make your function reference only as specific as you need, as per the Swift 2.2+ rules for function-type naming.

(This is actually an improvement over ObjC's @selector() directive, because the compiler's -Wundeclared-selector check verifies only that the named selector exists. The Swift function reference you pass to #selector checks existence, membership in a class, and type signature.)

There are a couple of extra caveats for the function references you pass to the #selector expression:

• Multiple functions with the same base name can be differentiated by their parameter labels using the aforementioned syntax for function references (e.g. insertSubview(_:at:) vs insertSubview(_:aboveSubview:)). But if a function has no parameters, the only way to disambiguate it is to use an as cast with the function's type signature (e.g. foo as () -> () vs foo(_:)).


• There's a special syntax for property getter/setter pairs in Swift 3.0+. For example, given a var foo: Int, you can use #selector(getter: MyClass.foo) or #selector(setter: MyClass.foo).

General notes:

Cases where #selector doesn't work, and naming: Sometimes you don't have a function reference to make a selector with (for example, with methods dynamically registered in the ObjC runtime). In that case, you can construct a Selector from a string: e.g. Selector("dynamicMethod:") — though you lose the compiler's validity checking. When you do that, you need to follow ObjC naming rules, including colons (:) for each parameter.

Selector availability: The method referenced by the selector must be exposed to the ObjC runtime. In Swift 4, every method exposed to ObjC must have its declaration prefaced with the @objc attribute. (In previous versions you got that attribute for free in some cases, but now you have to explicitly declare it.)

Remember that private symbols aren't exposed to the runtime, too — your method needs to have at least internal visibility.

Key paths: These are related to but not quite the same as selectors. There's a special syntax for these in Swift 3, too: e.g. chris.valueForKeyPath(#keyPath(Person.friends.firstName)). See SE-0062 for details. And even more KeyPath stuff in Swift 4, so make sure you're using the right KeyPath-based API instead of selectors if appropriate.

You can read more about selectors under Interacting with Objective-C APIs in Using Swift with Cocoa and Objective-C.

^{Note: Before Swift 2.2, Selector conformed to StringLiteralConvertible, so you might find old code where bare strings are passed to APIs that take selectors. You'll want to run "Convert to Current Swift Syntax" in Xcode to get those using #selector.}

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edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

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  Putting a string with the function name worked, NSSelectorFromString() works also.
  – Arbitur
  Jun 3 '14 at 5:36
  

  
  
  
  


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  I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
  – user1040049
  Jun 3 '14 at 20:32
  

  
  
  
  


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  This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
  – Daniel Schlaug
  Jul 6 '14 at 14:06
  
  
  

  
  
  
  


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  It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
  – JMFR
  Oct 28 '14 at 18:13
  

  
  
  
  


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  Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
  – yo.ian.g
  Dec 13 '14 at 18:59
  

  
  
  
  

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up vote
78
down vote

Here's a quick example on how to use the Selector class on Swift:

override func viewDidLoad() {

    super.viewDidLoad()



    var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))

    self.navigationItem.rightBarButtonItem = rightButton

}



func method() {

    // Something cool here   

}

Note that if the method passed as a string doesn't work, it will fail at runtime, not compile time, and crash your app. Be careful

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

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  which is horrible... is there a "NSStringFromSelector" type of thing ?
  – Lena Bru
  Jun 4 '14 at 22:47
  

  
  
  
  


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  can't believe they designed for unchecked selectors since objc had this
  – malhal
  Jun 6 '14 at 15:11
  

  
  
  
  


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  @malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
  – rickster
  Aug 8 '14 at 22:15
  

  
  
  
  


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  This answer is helpful but the answer below with @objc is more appropriate.
  – cynistersix
  Nov 12 '14 at 22:55
  

  
  
  
  


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  When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
  – levous
  Aug 4 '15 at 11:53
  

  
  
  
  

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up vote
44
down vote

Also, if your (Swift) class does not descend from an Objective-C class, then you must have a colon at the end of the target method name string and you must use the @objc property with your target method e.g.

var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))



@objc func method() {

    // Something cool here   

} 

otherwise you will get a "Unrecognised Selector" error at runtime.

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

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  1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
  – Yevhen Dubinin
  Dec 1 '14 at 0:31
  

  
  
  
  


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  @objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
  – Mike Taverne
  Feb 5 '15 at 19:03
  

  
  
  
  

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up vote
23
down vote

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

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edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

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  it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
  – apouche
  Oct 28 '15 at 10:40
  

  
  
  
  


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  dynamic func foo() { ... } also works
  – NAlexN
  Jan 30 '17 at 14:15
  
  
  

  
  
  
  


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  It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
  – Sajjon
  Apr 6 '17 at 8:27
  
  
  

  
  
  
  

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up vote
23
down vote

Swift 2.2+ and Swift 3 Update

Use the new #selector expression, which eliminates the need to use string literals making usage less error-prone. For reference:

Selector("keyboardDidHide:")

becomes

#selector(keyboardDidHide(_:))

See also: Swift Evolution Proposal

Note (Swift 4.0):

If using #selectoryou would need to mark the function as @objc

Example:

@objc func something(_ sender: UIButton)

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

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up vote
19
down vote

Just in case somebody else have the same problem I had with NSTimer where none of the other answers fixed the issue, is really important to mention that, if you are using a class that do not inherits from NSObject either directly or deep in the hierarchy(e.g. manually created swift files), none of the other answers will work even when is specified as follows:

let timer = NSTimer(timeInterval: 1, target: self, selector: "test", 

                    userInfo: nil, repeats: false)

func test () {}

Without changing anything else other than just making the class inherit from NSObject I stopped getting the "Unrecognized selector" Error and got my logic working as expected.

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

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  The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
  – eharo2
  Jul 22 '14 at 18:47
  

  
  
  
  


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  UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
  – Martin Cazares
  Jul 22 '14 at 19:10
  

  
  
  
  

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up vote
18
down vote

Swift 4.0

you create the Selector like below.

1.add the event to a button like:

button.addTarget(self, action: #selector(clickedButton(sender:)), for: UIControlEvents.touchUpInside)

and the function will be like below:

@objc func clickedButton(sender: AnyObject) {



}

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edited Mar 15 at 17:50

Kevin Singh

14117

answered Oct 15 '14 at 7:27

pravin salame

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  You forgot to put @objc before func which is required in Swift 4.
  – Vahid Amiri
  Jan 27 at 15:49
  

  
  
  
  

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up vote
14
down vote

If you want to pass a parameter to the function from the NSTimer then here is your solution:

var somethingToPass = "It worked"



let timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "tester:", userInfo: somethingToPass, repeats: false)



func tester(timer: NSTimer)

{

    let theStringToPrint = timer.userInfo as String

    println(theStringToPrint)

}

Include the colon in the selector text (tester:), and your parameter(s) go in userInfo.

Your function should take NSTimer as a parameter. Then just extract userInfo to get the parameter that passed.

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answered Aug 7 '14 at 15:29

Scooter

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  I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
  – iOS-Coder
  Jul 5 '15 at 12:19
  

  
  
  
  


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  @iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
  – David Ganster
  Oct 5 '15 at 21:30
  

  
  
  
  


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  @David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
  – iOS-Coder
  Oct 6 '15 at 22:27
  
  
  

  
  
  
  


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  Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
  – David Ganster
  Oct 7 '15 at 9:14
  

  
  
  
  

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up vote
10
down vote

Selectors are an internal representation of a method name in Objective-C. In Objective-C "@selector(methodName)" would convert a source-code method into a data type of SEL. Since you can't use the @selector syntax in Swift (rickster is on point there), you have to manually specify the method name as a String object directly, or by passing a String object to the Selector type. Here is an example:

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:"logout"

)

or

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:Selector("logout")

)

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answered Jun 5 '14 at 5:43

Jon Tsiros

398114

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up vote
8
down vote

Swift 4.1

With sample of tap gesture

let gestureRecognizer = UITapGestureRecognizer()

self.view.addGestureRecognizer(gestureRecognizer)

gestureRecognizer.addTarget(self, action: #selector(self.dismiss(completion:)))



// Use destination 'Class Name' directly, if you selector (function) is not in same class.

//gestureRecognizer.addTarget(self, action: #selector(DestinationClass.dismiss(completion:)))





@objc func dismiss(completion: (() -> Void)?) {

      self.dismiss(animated: true, completion: completion)

}

See Apple's document for more details about: Selector Expression

share|improve this answer

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

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  Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
  – Fogmeister
  Jun 9 '17 at 13:58
  

  
  
  
  


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  calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
  – Krunal
  Jun 9 '17 at 13:59
  
  
  

  
  
  
  


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  So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
  – Fogmeister
  Jun 9 '17 at 14:00
  
  
  

  
  
  
  


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  Also, which part of this is different from Swift 3?
  – Fogmeister
  Jun 9 '17 at 14:02
  

  
  
  
  


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  You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
  – Unome
  Sep 26 '17 at 15:33
  
  
  

  
  
  
  

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up vote
6
down vote

// for swift 2.2

// version 1

buttton.addTarget(self, action: #selector(ViewController.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(ViewController.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 2

buttton.addTarget(self, action: #selector(self.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(self.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 3

buttton.addTarget(self, action: #selector(tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(tappedButton2(_:)), forControlEvents: .TouchUpInside)



func tappedButton() {

  print("tapped")

}



func tappedButton2(sender: UIButton) {

  print("tapped 2")

}



// swift 3.x

button.addTarget(self, action: #selector(tappedButton(_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton) {

  // tapped

}



button.addTarget(self, action: #selector(tappedButton(_:_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton, _ event: UIEvent) {

  // tapped

}

share|improve this answer

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

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  it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
  – nyxee
  Jul 19 '17 at 22:24
  
  
  

  
  
  
  

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up vote
5
down vote

Create Refresh control using Selector method.   

    var refreshCntrl : UIRefreshControl!

    refreshCntrl = UIRefreshControl()

    refreshCntrl.tintColor = UIColor.whiteColor()

    refreshCntrl.attributedTitle = NSAttributedString(string: "Please Wait...")

    refreshCntrl.addTarget(self, action:"refreshControlValueChanged", forControlEvents: UIControlEvents.ValueChanged)

    atableView.addSubview(refreshCntrl)

//Refresh Control Method

func refreshControlValueChanged(){

    atableView.reloadData()

    refreshCntrl.endRefreshing()



}

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answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

add a comment | 

up vote
5
down vote

Since Swift 3.0 is published, it is even a little bit more subtle to declare a targetAction appropriate

class MyCustomView : UIView {



    func addTapGestureRecognizer() {



        // the "_" is important

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyCustomView.handleTapGesture(_:)))

        tapGestureRecognizer.numberOfTapsRequired = 1

        addGestureRecognizer(tapGestureRecognizer)

    }



    // since Swift 3.0 this "_" in the method implementation is very important to 

    // let the selector understand the targetAction

    func handleTapGesture(_ tapGesture : UITapGestureRecognizer) {



        if tapGesture.state == .ended {

            print("TapGesture detected")

        }

    }

}

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

add a comment | 

up vote
4
down vote

When using performSelector()

/addtarget()/NStimer.scheduledTimerWithInterval() methods your method (matching the selector) should be marked as

@objc

For Swift 2.0:

    {  

        //...

        self.performSelector(“performMethod”, withObject: nil , afterDelay: 0.5)

        //...





    //...

    btnHome.addTarget(self, action: “buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

    //...



    //...

     NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector : “timerMethod”, userInfo: nil, repeats: false)

    //...



}



@objc private func performMethod() {

…

}

@objc private func buttonPressed(sender:UIButton){

….

}

@objc private func timerMethod () {

….

}

For Swift 2.2,
you need to write '#selector()' instead of string and selector name so the possibilities of spelling error and crash due to that will not be there anymore. Below is example

self.performSelector(#selector(MyClass.performMethod), withObject: nil , afterDelay: 0.5)

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

add a comment | 

up vote
3
down vote

you create the Selector like below.

1.

UIBarButtonItem(

    title: "Some Title",

    style: UIBarButtonItemStyle.Done,

    target: self,

    action: "flatButtonPressed"

)

2.

flatButton.addTarget(self, action: "flatButtonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

Take note that the @selector syntax is gone and replaced with a simple String naming the method to call. There’s one area where we can all agree the verbosity got in the way. Of course, if we declared that there is a target method called flatButtonPressed: we better write one:

func flatButtonPressed(sender: AnyObject) {

  NSLog("flatButtonPressed")

}

set the timer:

    var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 

                    target: self, 

                    selector: Selector("flatButtonPressed"), 

                    userInfo: userInfo, 

                    repeats: true)

    let mainLoop = NSRunLoop.mainRunLoop()  //1

    mainLoop.addTimer(timer, forMode: NSDefaultRunLoopMode) //2 this two line is optinal

In order to be complete, here’s the flatButtonPressed

func flatButtonPressed(timer: NSTimer) {

}

share|improve this answer

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Do you have any source for "Take note that the @selector syntax is gone"?
  – winklerrr
  Mar 21 at 15:58
  

  
  
  
  

add a comment | 

up vote
3
down vote

I found many of these answers to be helpful but it wasn't clear how to do this with something that wasn't a button. I was adding a gesture recognizer to a UILabel in swift and struggled so here's what I found worked for me after reading everything above:

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: "labelTapped:")

Where the "Selector" was declared as:

func labelTapped(sender: UILabel) { }

Note that it is public and that I am not using the Selector() syntax but it is possible to do this as well.

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: Selector("labelTapped:"))

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

add a comment | 

up vote
3
down vote

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.

override func viewDidLoad() {

        super.viewDidLoad()



        navigationItem.rightBarButtonItem =

            UIBarButtonItem(barButtonSystemItem: .Add, target: self,

                            action: #selector(addNewFireflyRefernce))

    }



    func addNewFireflyReference() {

        gratuitousReferences.append("Curse your sudden but inevitable betrayal!")

    }

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

add a comment | 

up vote
2
down vote

It may be useful to note where you setup the control that triggers the action matters.

For example, I have found that when setting up a UIBarButtonItem, I had to create the button within viewDidLoad or else I would get an unrecognized selector exception.

override func viewDidLoad() {

        super.viewDidLoad()





        // add button

        let addButton = UIBarButtonItem(image: UIImage(named: "746-plus-circle.png"), style: UIBarButtonItemStyle.Plain, target: self, action: Selector("addAction:"))

        self.navigationItem.rightBarButtonItem = addButton

    }





    func addAction(send: AnyObject?) {



        NSLog("addAction")

    }

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

add a comment | 

up vote
1
down vote

Change as a simple string naming in the method calling for selector syntax

var timer1 : NSTimer? = nil

timer1= NSTimer(timeInterval: 0.1, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

After that, type func test().

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

add a comment | 

up vote
0
down vote

For swift 3

let timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.test), userInfo: nil, repeats: true)

Function Declaration In Same Class

func test()

{

    // my function

} 

share|improve this answer

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

add a comment | 

up vote
0
down vote

For Swift 3

//Sample code to create timer

Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)



WHERE

timeInterval:- Interval in which timer should fire like 1s, 10s, 100s etc. [Its value is in secs]

target:- function which pointed to class. So here I am pointing to current class.

selector:- function that will execute when timer fires.



func updateTimer(){

    //Implemetation 

} 



repeats:- true/false specifies that timer should call again n again.

share|improve this answer

answered May 19 at 17:03

CrazyPro007

785

add a comment | 

up vote
0
down vote

Selector in Swift 4:

button.addTarget(self, action: #selector(buttonTapped(sender:)), for: UIControlEvents.touchUpInside)

share|improve this answer

edited yesterday

Moritz

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

add a comment | 

protected by Community♦ Mar 1 '15 at 21:02

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accepted

Swift itself doesn't use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.)

But there are still a number of important ObjC-based APIs that use selectors, including timers and the target/action pattern. Swift provides the Selector type for working with these. (Swift automatically uses this in place of ObjC's SEL type.)

In Swift 2.2 (Xcode 7.3) and later (including Swift 3 / Xcode 8 and Swift 4 / Xcode 9):

You can construct a Selector from a Swift function type using the #selector expression.

let timer = Timer(timeInterval: 1, target: object,

                  selector: #selector(MyClass.test),

                  userInfo: nil, repeats: false)

button.addTarget(object, action: #selector(MyClass.buttonTapped),

                 for: .touchUpInside)

view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),

             with: button, with: otherButton)

The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pairs that actually exist and are eligible for use as selectors (see "Selector availability" below). You're also free to make your function reference only as specific as you need, as per the Swift 2.2+ rules for function-type naming.

(This is actually an improvement over ObjC's @selector() directive, because the compiler's -Wundeclared-selector check verifies only that the named selector exists. The Swift function reference you pass to #selector checks existence, membership in a class, and type signature.)

There are a couple of extra caveats for the function references you pass to the #selector expression:

• Multiple functions with the same base name can be differentiated by their parameter labels using the aforementioned syntax for function references (e.g. insertSubview(_:at:) vs insertSubview(_:aboveSubview:)). But if a function has no parameters, the only way to disambiguate it is to use an as cast with the function's type signature (e.g. foo as () -> () vs foo(_:)).


• There's a special syntax for property getter/setter pairs in Swift 3.0+. For example, given a var foo: Int, you can use #selector(getter: MyClass.foo) or #selector(setter: MyClass.foo).

General notes:

Cases where #selector doesn't work, and naming: Sometimes you don't have a function reference to make a selector with (for example, with methods dynamically registered in the ObjC runtime). In that case, you can construct a Selector from a string: e.g. Selector("dynamicMethod:") — though you lose the compiler's validity checking. When you do that, you need to follow ObjC naming rules, including colons (:) for each parameter.

Selector availability: The method referenced by the selector must be exposed to the ObjC runtime. In Swift 4, every method exposed to ObjC must have its declaration prefaced with the @objc attribute. (In previous versions you got that attribute for free in some cases, but now you have to explicitly declare it.)

Remember that private symbols aren't exposed to the runtime, too — your method needs to have at least internal visibility.

Key paths: These are related to but not quite the same as selectors. There's a special syntax for these in Swift 3, too: e.g. chris.valueForKeyPath(#keyPath(Person.friends.firstName)). See SE-0062 for details. And even more KeyPath stuff in Swift 4, so make sure you're using the right KeyPath-based API instead of selectors if appropriate.

You can read more about selectors under Interacting with Objective-C APIs in Using Swift with Cocoa and Objective-C.

^{Note: Before Swift 2.2, Selector conformed to StringLiteralConvertible, so you might find old code where bare strings are passed to APIs that take selectors. You'll want to run "Convert to Current Swift Syntax" in Xcode to get those using #selector.}

share|improve this answer

edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Putting a string with the function name worked, NSSelectorFromString() works also.
  – Arbitur
  Jun 3 '14 at 5:36
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
  – user1040049
  Jun 3 '14 at 20:32
  

  
  
  
  


• 
  
  
  

  
  9
  

  
  
  
  
  
  

  
  This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
  – Daniel Schlaug
  Jul 6 '14 at 14:06
  
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
  – JMFR
  Oct 28 '14 at 18:13
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
  – yo.ian.g
  Dec 13 '14 at 18:59
  

  
  
  
  

 | 
show 11 more comments

up vote
880
down vote



accepted

Swift itself doesn't use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.)

But there are still a number of important ObjC-based APIs that use selectors, including timers and the target/action pattern. Swift provides the Selector type for working with these. (Swift automatically uses this in place of ObjC's SEL type.)

In Swift 2.2 (Xcode 7.3) and later (including Swift 3 / Xcode 8 and Swift 4 / Xcode 9):

You can construct a Selector from a Swift function type using the #selector expression.

let timer = Timer(timeInterval: 1, target: object,

                  selector: #selector(MyClass.test),

                  userInfo: nil, repeats: false)

button.addTarget(object, action: #selector(MyClass.buttonTapped),

                 for: .touchUpInside)

view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),

             with: button, with: otherButton)

The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pairs that actually exist and are eligible for use as selectors (see "Selector availability" below). You're also free to make your function reference only as specific as you need, as per the Swift 2.2+ rules for function-type naming.

(This is actually an improvement over ObjC's @selector() directive, because the compiler's -Wundeclared-selector check verifies only that the named selector exists. The Swift function reference you pass to #selector checks existence, membership in a class, and type signature.)

There are a couple of extra caveats for the function references you pass to the #selector expression:

• Multiple functions with the same base name can be differentiated by their parameter labels using the aforementioned syntax for function references (e.g. insertSubview(_:at:) vs insertSubview(_:aboveSubview:)). But if a function has no parameters, the only way to disambiguate it is to use an as cast with the function's type signature (e.g. foo as () -> () vs foo(_:)).


• There's a special syntax for property getter/setter pairs in Swift 3.0+. For example, given a var foo: Int, you can use #selector(getter: MyClass.foo) or #selector(setter: MyClass.foo).

General notes:

Cases where #selector doesn't work, and naming: Sometimes you don't have a function reference to make a selector with (for example, with methods dynamically registered in the ObjC runtime). In that case, you can construct a Selector from a string: e.g. Selector("dynamicMethod:") — though you lose the compiler's validity checking. When you do that, you need to follow ObjC naming rules, including colons (:) for each parameter.

Selector availability: The method referenced by the selector must be exposed to the ObjC runtime. In Swift 4, every method exposed to ObjC must have its declaration prefaced with the @objc attribute. (In previous versions you got that attribute for free in some cases, but now you have to explicitly declare it.)

Remember that private symbols aren't exposed to the runtime, too — your method needs to have at least internal visibility.

Key paths: These are related to but not quite the same as selectors. There's a special syntax for these in Swift 3, too: e.g. chris.valueForKeyPath(#keyPath(Person.friends.firstName)). See SE-0062 for details. And even more KeyPath stuff in Swift 4, so make sure you're using the right KeyPath-based API instead of selectors if appropriate.

You can read more about selectors under Interacting with Objective-C APIs in Using Swift with Cocoa and Objective-C.

^{Note: Before Swift 2.2, Selector conformed to StringLiteralConvertible, so you might find old code where bare strings are passed to APIs that take selectors. You'll want to run "Convert to Current Swift Syntax" in Xcode to get those using #selector.}

share|improve this answer

edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Putting a string with the function name worked, NSSelectorFromString() works also.
  – Arbitur
  Jun 3 '14 at 5:36
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
  – user1040049
  Jun 3 '14 at 20:32
  

  
  
  
  


• 
  
  
  

  
  9
  

  
  
  
  
  
  

  
  This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
  – Daniel Schlaug
  Jul 6 '14 at 14:06
  
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
  – JMFR
  Oct 28 '14 at 18:13
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
  – yo.ian.g
  Dec 13 '14 at 18:59
  

  
  
  
  

 | 
show 11 more comments

up vote
880
down vote



accepted

up vote
880
down vote



accepted

Swift itself doesn't use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.)

But there are still a number of important ObjC-based APIs that use selectors, including timers and the target/action pattern. Swift provides the Selector type for working with these. (Swift automatically uses this in place of ObjC's SEL type.)

In Swift 2.2 (Xcode 7.3) and later (including Swift 3 / Xcode 8 and Swift 4 / Xcode 9):

You can construct a Selector from a Swift function type using the #selector expression.

let timer = Timer(timeInterval: 1, target: object,

                  selector: #selector(MyClass.test),

                  userInfo: nil, repeats: false)

button.addTarget(object, action: #selector(MyClass.buttonTapped),

                 for: .touchUpInside)

view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),

             with: button, with: otherButton)

The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pairs that actually exist and are eligible for use as selectors (see "Selector availability" below). You're also free to make your function reference only as specific as you need, as per the Swift 2.2+ rules for function-type naming.

(This is actually an improvement over ObjC's @selector() directive, because the compiler's -Wundeclared-selector check verifies only that the named selector exists. The Swift function reference you pass to #selector checks existence, membership in a class, and type signature.)

There are a couple of extra caveats for the function references you pass to the #selector expression:

• Multiple functions with the same base name can be differentiated by their parameter labels using the aforementioned syntax for function references (e.g. insertSubview(_:at:) vs insertSubview(_:aboveSubview:)). But if a function has no parameters, the only way to disambiguate it is to use an as cast with the function's type signature (e.g. foo as () -> () vs foo(_:)).


• There's a special syntax for property getter/setter pairs in Swift 3.0+. For example, given a var foo: Int, you can use #selector(getter: MyClass.foo) or #selector(setter: MyClass.foo).

General notes:

Cases where #selector doesn't work, and naming: Sometimes you don't have a function reference to make a selector with (for example, with methods dynamically registered in the ObjC runtime). In that case, you can construct a Selector from a string: e.g. Selector("dynamicMethod:") — though you lose the compiler's validity checking. When you do that, you need to follow ObjC naming rules, including colons (:) for each parameter.

Selector availability: The method referenced by the selector must be exposed to the ObjC runtime. In Swift 4, every method exposed to ObjC must have its declaration prefaced with the @objc attribute. (In previous versions you got that attribute for free in some cases, but now you have to explicitly declare it.)

Remember that private symbols aren't exposed to the runtime, too — your method needs to have at least internal visibility.

Key paths: These are related to but not quite the same as selectors. There's a special syntax for these in Swift 3, too: e.g. chris.valueForKeyPath(#keyPath(Person.friends.firstName)). See SE-0062 for details. And even more KeyPath stuff in Swift 4, so make sure you're using the right KeyPath-based API instead of selectors if appropriate.

You can read more about selectors under Interacting with Objective-C APIs in Using Swift with Cocoa and Objective-C.

^{Note: Before Swift 2.2, Selector conformed to StringLiteralConvertible, so you might find old code where bare strings are passed to APIs that take selectors. You'll want to run "Convert to Current Swift Syntax" in Xcode to get those using #selector.}

share|improve this answer

edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

Swift itself doesn't use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.)

But there are still a number of important ObjC-based APIs that use selectors, including timers and the target/action pattern. Swift provides the Selector type for working with these. (Swift automatically uses this in place of ObjC's SEL type.)

In Swift 2.2 (Xcode 7.3) and later (including Swift 3 / Xcode 8 and Swift 4 / Xcode 9):

You can construct a Selector from a Swift function type using the #selector expression.

let timer = Timer(timeInterval: 1, target: object,

                  selector: #selector(MyClass.test),

                  userInfo: nil, repeats: false)

button.addTarget(object, action: #selector(MyClass.buttonTapped),

                 for: .touchUpInside)

view.perform(#selector(UIView.insertSubview(_:aboveSubview:)),

             with: button, with: otherButton)

The great thing about this approach? A function reference is checked by the Swift compiler, so you can use the #selector expression only with class/method pairs that actually exist and are eligible for use as selectors (see "Selector availability" below). You're also free to make your function reference only as specific as you need, as per the Swift 2.2+ rules for function-type naming.

(This is actually an improvement over ObjC's @selector() directive, because the compiler's -Wundeclared-selector check verifies only that the named selector exists. The Swift function reference you pass to #selector checks existence, membership in a class, and type signature.)

There are a couple of extra caveats for the function references you pass to the #selector expression:

• Multiple functions with the same base name can be differentiated by their parameter labels using the aforementioned syntax for function references (e.g. insertSubview(_:at:) vs insertSubview(_:aboveSubview:)). But if a function has no parameters, the only way to disambiguate it is to use an as cast with the function's type signature (e.g. foo as () -> () vs foo(_:)).


• There's a special syntax for property getter/setter pairs in Swift 3.0+. For example, given a var foo: Int, you can use #selector(getter: MyClass.foo) or #selector(setter: MyClass.foo).

General notes:

Cases where #selector doesn't work, and naming: Sometimes you don't have a function reference to make a selector with (for example, with methods dynamically registered in the ObjC runtime). In that case, you can construct a Selector from a string: e.g. Selector("dynamicMethod:") — though you lose the compiler's validity checking. When you do that, you need to follow ObjC naming rules, including colons (:) for each parameter.

Selector availability: The method referenced by the selector must be exposed to the ObjC runtime. In Swift 4, every method exposed to ObjC must have its declaration prefaced with the @objc attribute. (In previous versions you got that attribute for free in some cases, but now you have to explicitly declare it.)

Remember that private symbols aren't exposed to the runtime, too — your method needs to have at least internal visibility.

Key paths: These are related to but not quite the same as selectors. There's a special syntax for these in Swift 3, too: e.g. chris.valueForKeyPath(#keyPath(Person.friends.firstName)). See SE-0062 for details. And even more KeyPath stuff in Swift 4, so make sure you're using the right KeyPath-based API instead of selectors if appropriate.

You can read more about selectors under Interacting with Objective-C APIs in Using Swift with Cocoa and Objective-C.

^{Note: Before Swift 2.2, Selector conformed to StringLiteralConvertible, so you might find old code where bare strings are passed to APIs that take selectors. You'll want to run "Convert to Current Swift Syntax" in Xcode to get those using #selector.}

share|improve this answer

edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

share|improve this answer

share|improve this answer

edited Sep 26 '17 at 20:40

edited Sep 26 '17 at 20:40

edited Sep 26 '17 at 20:40

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

answered Jun 3 '14 at 5:27

rickster

99.8k21202257

99.8k21202257

• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Putting a string with the function name worked, NSSelectorFromString() works also.
  – Arbitur
  Jun 3 '14 at 5:36
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
  – user1040049
  Jun 3 '14 at 20:32
  

  
  
  
  


• 
  
  
  

  
  9
  

  
  
  
  
  
  

  
  This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
  – Daniel Schlaug
  Jul 6 '14 at 14:06
  
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
  – JMFR
  Oct 28 '14 at 18:13
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
  – yo.ian.g
  Dec 13 '14 at 18:59
  

  
  
  
  

 | 
show 11 more comments

• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Putting a string with the function name worked, NSSelectorFromString() works also.
  – Arbitur
  Jun 3 '14 at 5:36
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
  – user1040049
  Jun 3 '14 at 20:32
  

  
  
  
  


• 
  
  
  

  
  9
  

  
  
  
  
  
  

  
  This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
  – Daniel Schlaug
  Jul 6 '14 at 14:06
  
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
  – JMFR
  Oct 28 '14 at 18:13
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
  – yo.ian.g
  Dec 13 '14 at 18:59
  

  
  
  
  

7

7

Putting a string with the function name worked, NSSelectorFromString() works also.
– Arbitur
Jun 3 '14 at 5:36

Putting a string with the function name worked, NSSelectorFromString() works also.
– Arbitur
Jun 3 '14 at 5:36

5

5

I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
– user1040049
Jun 3 '14 at 20:32

I'd like to mention that while "Interacting with Objective-C APIs" is on the website, it is NOT in 'The Swift Programming Language' book.
– user1040049
Jun 3 '14 at 20:32

9

9

This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
– Daniel Schlaug
Jul 6 '14 at 14:06

This should probably mention that the selector needs a ":" at the end if it takes an argument. (E.g. test() -> "test" & test(this:String) -> "test:")
– Daniel Schlaug
Jul 6 '14 at 14:06

2

2

It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
– JMFR
Oct 28 '14 at 18:13

It should also be pointed out that the Cocoa frameworks expect an Objective-C style method name. If your method takes an argument you will need a ':' if it takes 2 arguments, size:andShape:, if the first argument is named you may need a With, i.e. initWithData: for func init(Data data: NSData)
– JMFR
Oct 28 '14 at 18:13

5

5

Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
– yo.ian.g
Dec 13 '14 at 18:59

Is there anyway to add validation around passing the "selector" as a string? IE compiler warn us when we misspell, etc.
– yo.ian.g
Dec 13 '14 at 18:59

 | 
show 11 more comments

up vote
78
down vote

Here's a quick example on how to use the Selector class on Swift:

override func viewDidLoad() {

    super.viewDidLoad()



    var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))

    self.navigationItem.rightBarButtonItem = rightButton

}



func method() {

    // Something cool here   

}

Note that if the method passed as a string doesn't work, it will fail at runtime, not compile time, and crash your app. Be careful

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

• 
  
  
  

  
  12
  

  
  
  
  
  
  

  
  which is horrible... is there a "NSStringFromSelector" type of thing ?
  – Lena Bru
  Jun 4 '14 at 22:47
  

  
  
  
  


• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  can't believe they designed for unchecked selectors since objc had this
  – malhal
  Jun 6 '14 at 15:11
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  @malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
  – rickster
  Aug 8 '14 at 22:15
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  This answer is helpful but the answer below with @objc is more appropriate.
  – cynistersix
  Nov 12 '14 at 22:55
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
  – levous
  Aug 4 '15 at 11:53
  

  
  
  
  

 | 
show 1 more comment

up vote
78
down vote

Here's a quick example on how to use the Selector class on Swift:

override func viewDidLoad() {

    super.viewDidLoad()



    var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))

    self.navigationItem.rightBarButtonItem = rightButton

}



func method() {

    // Something cool here   

}

Note that if the method passed as a string doesn't work, it will fail at runtime, not compile time, and crash your app. Be careful

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

• 
  
  
  

  
  12
  

  
  
  
  
  
  

  
  which is horrible... is there a "NSStringFromSelector" type of thing ?
  – Lena Bru
  Jun 4 '14 at 22:47
  

  
  
  
  


• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  can't believe they designed for unchecked selectors since objc had this
  – malhal
  Jun 6 '14 at 15:11
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  @malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
  – rickster
  Aug 8 '14 at 22:15
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  This answer is helpful but the answer below with @objc is more appropriate.
  – cynistersix
  Nov 12 '14 at 22:55
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
  – levous
  Aug 4 '15 at 11:53
  

  
  
  
  

 | 
show 1 more comment

up vote
78
down vote

up vote
78
down vote

Here's a quick example on how to use the Selector class on Swift:

override func viewDidLoad() {

    super.viewDidLoad()



    var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))

    self.navigationItem.rightBarButtonItem = rightButton

}



func method() {

    // Something cool here   

}

Note that if the method passed as a string doesn't work, it will fail at runtime, not compile time, and crash your app. Be careful

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

Here's a quick example on how to use the Selector class on Swift:

override func viewDidLoad() {

    super.viewDidLoad()



    var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))

    self.navigationItem.rightBarButtonItem = rightButton

}



func method() {

    // Something cool here   

}

Note that if the method passed as a string doesn't work, it will fail at runtime, not compile time, and crash your app. Be careful

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

share|improve this answer

share|improve this answer

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

answered Jun 3 '14 at 5:31

Oscar Swanros

16.4k52847

16.4k52847

• 
  
  
  

  
  12
  

  
  
  
  
  
  

  
  which is horrible... is there a "NSStringFromSelector" type of thing ?
  – Lena Bru
  Jun 4 '14 at 22:47
  

  
  
  
  


• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  can't believe they designed for unchecked selectors since objc had this
  – malhal
  Jun 6 '14 at 15:11
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  @malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
  – rickster
  Aug 8 '14 at 22:15
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  This answer is helpful but the answer below with @objc is more appropriate.
  – cynistersix
  Nov 12 '14 at 22:55
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
  – levous
  Aug 4 '15 at 11:53
  

  
  
  
  

 | 
show 1 more comment

• 
  
  
  

  
  12
  

  
  
  
  
  
  

  
  which is horrible... is there a "NSStringFromSelector" type of thing ?
  – Lena Bru
  Jun 4 '14 at 22:47
  

  
  
  
  


• 
  
  
  

  
  11
  

  
  
  
  
  
  

  
  can't believe they designed for unchecked selectors since objc had this
  – malhal
  Jun 6 '14 at 15:11
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  @malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
  – rickster
  Aug 8 '14 at 22:15
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  This answer is helpful but the answer below with @objc is more appropriate.
  – cynistersix
  Nov 12 '14 at 22:55
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
  – levous
  Aug 4 '15 at 11:53
  

  
  
  
  

12

12

which is horrible... is there a "NSStringFromSelector" type of thing ?
– Lena Bru
Jun 4 '14 at 22:47

which is horrible... is there a "NSStringFromSelector" type of thing ?
– Lena Bru
Jun 4 '14 at 22:47

11

11

can't believe they designed for unchecked selectors since objc had this
– malhal
Jun 6 '14 at 15:11

can't believe they designed for unchecked selectors since objc had this
– malhal
Jun 6 '14 at 15:11

4

4

@malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
– rickster
Aug 8 '14 at 22:15

@malcomhall: @selector is handy, but it's not enforced as formally as you might think. "Undeclared selector" is merely a warning from the compiler, because new selectors can always be introduced at run time. Verifiable/refactorable selector references in Swift would be a good feature request to make, though.
– rickster
Aug 8 '14 at 22:15

2

2

This answer is helpful but the answer below with @objc is more appropriate.
– cynistersix
Nov 12 '14 at 22:55

This answer is helpful but the answer below with @objc is more appropriate.
– cynistersix
Nov 12 '14 at 22:55

When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
– levous
Aug 4 '15 at 11:53

When you are passing the selector string in as a variable or parameter, you'll need to let the compiler know its a selector using the Selector() function. thanks
– levous
Aug 4 '15 at 11:53

 | 
show 1 more comment

up vote
44
down vote

Also, if your (Swift) class does not descend from an Objective-C class, then you must have a colon at the end of the target method name string and you must use the @objc property with your target method e.g.

var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))



@objc func method() {

    // Something cool here   

} 

otherwise you will get a "Unrecognised Selector" error at runtime.

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

57743

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
  – Yevhen Dubinin
  Dec 1 '14 at 0:31
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
  – Mike Taverne
  Feb 5 '15 at 19:03
  

  
  
  
  

add a comment | 

up vote
44
down vote

Also, if your (Swift) class does not descend from an Objective-C class, then you must have a colon at the end of the target method name string and you must use the @objc property with your target method e.g.

var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))



@objc func method() {

    // Something cool here   

} 

otherwise you will get a "Unrecognised Selector" error at runtime.

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

57743

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
  – Yevhen Dubinin
  Dec 1 '14 at 0:31
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
  – Mike Taverne
  Feb 5 '15 at 19:03
  

  
  
  
  

add a comment | 

up vote
44
down vote

up vote
44
down vote

Also, if your (Swift) class does not descend from an Objective-C class, then you must have a colon at the end of the target method name string and you must use the @objc property with your target method e.g.

var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))



@objc func method() {

    // Something cool here   

} 

otherwise you will get a "Unrecognised Selector" error at runtime.

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

57743

Also, if your (Swift) class does not descend from an Objective-C class, then you must have a colon at the end of the target method name string and you must use the @objc property with your target method e.g.

var rightButton = UIBarButtonItem(title: "Title", style: UIBarButtonItemStyle.Plain, target: self, action: Selector("method"))



@objc func method() {

    // Something cool here   

} 

otherwise you will get a "Unrecognised Selector" error at runtime.

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

57743

share|improve this answer

share|improve this answer

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

edited Mar 8 '15 at 12:49

Leo Natan

51.4k8123173

51.4k8123173

answered Jun 24 '14 at 15:23

user3771857

57743

answered Jun 24 '14 at 15:23

user3771857

57743

answered Jun 24 '14 at 15:23

user3771857

57743

57743

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
  – Yevhen Dubinin
  Dec 1 '14 at 0:31
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
  – Mike Taverne
  Feb 5 '15 at 19:03
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
  – Yevhen Dubinin
  Dec 1 '14 at 0:31
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
  – Mike Taverne
  Feb 5 '15 at 19:03
  

  
  
  
  

3

3

1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
– Yevhen Dubinin
Dec 1 '14 at 0:31

1. selectors w/ a colon must take an argument 2. according to Apple docs timer's actions should take NSTimer argument 3. Selector keyword is not mandatory. So in this case signature must be @objc func method(timer: NSTimer) {/*code*/}
– Yevhen Dubinin
Dec 1 '14 at 0:31

@objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
– Mike Taverne
Feb 5 '15 at 19:03

@objc worked for me. I didn't need to include timer: NSTimer in my method signature for it to be called.
– Mike Taverne
Feb 5 '15 at 19:03

add a comment | 

up vote
23
down vote

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

share|improve this answer

edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

• 
  
  
  

  
  13
  

  
  
  
  
  
  

  
  it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
  – apouche
  Oct 28 '15 at 10:40
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  dynamic func foo() { ... } also works
  – NAlexN
  Jan 30 '17 at 14:15
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
  – Sajjon
  Apr 6 '17 at 8:27
  
  
  

  
  
  
  

add a comment | 

up vote
23
down vote

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

share|improve this answer

edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

• 
  
  
  

  
  13
  

  
  
  
  
  
  

  
  it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
  – apouche
  Oct 28 '15 at 10:40
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  dynamic func foo() { ... } also works
  – NAlexN
  Jan 30 '17 at 14:15
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
  – Sajjon
  Apr 6 '17 at 8:27
  
  
  

  
  
  
  

add a comment | 

up vote
23
down vote

up vote
23
down vote

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

share|improve this answer

edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

share|improve this answer

edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

share|improve this answer

share|improve this answer

edited May 10 '15 at 19:16

edited May 10 '15 at 19:16

edited May 10 '15 at 19:16

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

answered Apr 10 '15 at 18:08

Rob Sanders

3,21821735

3,21821735

• 
  
  
  

  
  13
  

  
  
  
  
  
  

  
  it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
  – apouche
  Oct 28 '15 at 10:40
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  dynamic func foo() { ... } also works
  – NAlexN
  Jan 30 '17 at 14:15
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
  – Sajjon
  Apr 6 '17 at 8:27
  
  
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  13
  

  
  
  
  
  
  

  
  it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
  – apouche
  Oct 28 '15 at 10:40
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  dynamic func foo() { ... } also works
  – NAlexN
  Jan 30 '17 at 14:15
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
  – Sajjon
  Apr 6 '17 at 8:27
  
  
  

  
  
  
  

13

13

it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
– apouche
Oct 28 '15 at 10:40

it doesn't have to be public you can still keep the method private but add objc before it's declaration. Ex: @objc private func foo() { ... then you can use "foo" as a selector as much you like
– apouche
Oct 28 '15 at 10:40

dynamic func foo() { ... } also works
– NAlexN
Jan 30 '17 at 14:15

dynamic func foo() { ... } also works
– NAlexN
Jan 30 '17 at 14:15

It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
– Sajjon
Apr 6 '17 at 8:27

It can also be internal, thus not specifying any access modifier. I often use this pattern: //MARK: - Selector Methodsn extension MyController {n func buttonPressed(_ button: UIButton) {
– Sajjon
Apr 6 '17 at 8:27

add a comment | 

up vote
23
down vote

Swift 2.2+ and Swift 3 Update

Use the new #selector expression, which eliminates the need to use string literals making usage less error-prone. For reference:

Selector("keyboardDidHide:")

becomes

#selector(keyboardDidHide(_:))

See also: Swift Evolution Proposal

Note (Swift 4.0):

If using #selectoryou would need to mark the function as @objc

Example:

@objc func something(_ sender: UIButton)

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

add a comment | 

up vote
23
down vote

Swift 2.2+ and Swift 3 Update

Use the new #selector expression, which eliminates the need to use string literals making usage less error-prone. For reference:

Selector("keyboardDidHide:")

becomes

#selector(keyboardDidHide(_:))

See also: Swift Evolution Proposal

Note (Swift 4.0):

If using #selectoryou would need to mark the function as @objc

Example:

@objc func something(_ sender: UIButton)

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

add a comment | 

up vote
23
down vote

up vote
23
down vote

Swift 2.2+ and Swift 3 Update

Use the new #selector expression, which eliminates the need to use string literals making usage less error-prone. For reference:

Selector("keyboardDidHide:")

becomes

#selector(keyboardDidHide(_:))

See also: Swift Evolution Proposal

Note (Swift 4.0):

If using #selectoryou would need to mark the function as @objc

Example:

@objc func something(_ sender: UIButton)

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

Swift 2.2+ and Swift 3 Update

Use the new #selector expression, which eliminates the need to use string literals making usage less error-prone. For reference:

Selector("keyboardDidHide:")

becomes

#selector(keyboardDidHide(_:))

See also: Swift Evolution Proposal

Note (Swift 4.0):

If using #selectoryou would need to mark the function as @objc

Example:

@objc func something(_ sender: UIButton)

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

share|improve this answer

share|improve this answer

edited Nov 22 '17 at 5:31

Joseph Francis

288417

edited Nov 22 '17 at 5:31

Joseph Francis

288417

edited Nov 22 '17 at 5:31

Joseph Francis

288417

288417

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

answered Apr 6 '16 at 16:06

Kyle Clegg

28.6k25117128

28.6k25117128

add a comment | 

add a comment | 

up vote
19
down vote

Just in case somebody else have the same problem I had with NSTimer where none of the other answers fixed the issue, is really important to mention that, if you are using a class that do not inherits from NSObject either directly or deep in the hierarchy(e.g. manually created swift files), none of the other answers will work even when is specified as follows:

let timer = NSTimer(timeInterval: 1, target: self, selector: "test", 

                    userInfo: nil, repeats: false)

func test () {}

Without changing anything else other than just making the class inherit from NSObject I stopped getting the "Unrecognized selector" Error and got my logic working as expected.

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

• 
  
  
  

  
  

  
  
  
  
  
  

  
  The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
  – eharo2
  Jul 22 '14 at 18:47
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
  – Martin Cazares
  Jul 22 '14 at 19:10
  

  
  
  
  

add a comment | 

up vote
19
down vote

Just in case somebody else have the same problem I had with NSTimer where none of the other answers fixed the issue, is really important to mention that, if you are using a class that do not inherits from NSObject either directly or deep in the hierarchy(e.g. manually created swift files), none of the other answers will work even when is specified as follows:

let timer = NSTimer(timeInterval: 1, target: self, selector: "test", 

                    userInfo: nil, repeats: false)

func test () {}

Without changing anything else other than just making the class inherit from NSObject I stopped getting the "Unrecognized selector" Error and got my logic working as expected.

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

• 
  
  
  

  
  

  
  
  
  
  
  

  
  The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
  – eharo2
  Jul 22 '14 at 18:47
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
  – Martin Cazares
  Jul 22 '14 at 19:10
  

  
  
  
  

add a comment | 

up vote
19
down vote

up vote
19
down vote

Just in case somebody else have the same problem I had with NSTimer where none of the other answers fixed the issue, is really important to mention that, if you are using a class that do not inherits from NSObject either directly or deep in the hierarchy(e.g. manually created swift files), none of the other answers will work even when is specified as follows:

let timer = NSTimer(timeInterval: 1, target: self, selector: "test", 

                    userInfo: nil, repeats: false)

func test () {}

Without changing anything else other than just making the class inherit from NSObject I stopped getting the "Unrecognized selector" Error and got my logic working as expected.

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

Just in case somebody else have the same problem I had with NSTimer where none of the other answers fixed the issue, is really important to mention that, if you are using a class that do not inherits from NSObject either directly or deep in the hierarchy(e.g. manually created swift files), none of the other answers will work even when is specified as follows:

let timer = NSTimer(timeInterval: 1, target: self, selector: "test", 

                    userInfo: nil, repeats: false)

func test () {}

Without changing anything else other than just making the class inherit from NSObject I stopped getting the "Unrecognized selector" Error and got my logic working as expected.

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

share|improve this answer

share|improve this answer

edited May 31 '15 at 6:59

royhowie

8,851133658

edited May 31 '15 at 6:59

royhowie

8,851133658

edited May 31 '15 at 6:59

royhowie

8,851133658

8,851133658

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

answered Jul 13 '14 at 5:31

Martin Cazares

10.9k73752

10.9k73752

• 
  
  
  

  
  

  
  
  
  
  
  

  
  The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
  – eharo2
  Jul 22 '14 at 18:47
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
  – Martin Cazares
  Jul 22 '14 at 19:10
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
  – eharo2
  Jul 22 '14 at 18:47
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
  – Martin Cazares
  Jul 22 '14 at 19:10
  

  
  
  
  

The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
– eharo2
Jul 22 '14 at 18:47

The issue with this alternative is that you can´t change a class (let´s say ViewController) to inherit from NSObject, given that you need the ViewController class implemented stuff (e.g. viewDidLoad()). Any idea how to call a Swift function within a ViewController using NSTimer?... e
– eharo2
Jul 22 '14 at 18:47

1

1

UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
– Martin Cazares
Jul 22 '14 at 19:10

UIViewController already inherits from NSObject, most classes exposed by the SDK do, this example is for your own created classes that require NSTimer functionality...
– Martin Cazares
Jul 22 '14 at 19:10

add a comment | 

up vote
18
down vote

Swift 4.0

you create the Selector like below.

1.add the event to a button like:

button.addTarget(self, action: #selector(clickedButton(sender:)), for: UIControlEvents.touchUpInside)

and the function will be like below:

@objc func clickedButton(sender: AnyObject) {



}

share|improve this answer

edited Mar 15 at 17:50

Kevin Singh

14117

answered Oct 15 '14 at 7:27

pravin salame

23924

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  You forgot to put @objc before func which is required in Swift 4.
  – Vahid Amiri
  Jan 27 at 15:49
  

  
  
  
  

add a comment | 

up vote
18
down vote

Swift 4.0

you create the Selector like below.

1.add the event to a button like:

button.addTarget(self, action: #selector(clickedButton(sender:)), for: UIControlEvents.touchUpInside)

and the function will be like below:

@objc func clickedButton(sender: AnyObject) {



}

share|improve this answer

edited Mar 15 at 17:50

Kevin Singh

14117

answered Oct 15 '14 at 7:27

pravin salame

23924

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  You forgot to put @objc before func which is required in Swift 4.
  – Vahid Amiri
  Jan 27 at 15:49
  

  
  
  
  

add a comment | 

up vote
18
down vote

up vote
18
down vote

Swift 4.0

you create the Selector like below.

1.add the event to a button like:

button.addTarget(self, action: #selector(clickedButton(sender:)), for: UIControlEvents.touchUpInside)

and the function will be like below:

@objc func clickedButton(sender: AnyObject) {



}

share|improve this answer

edited Mar 15 at 17:50

Kevin Singh

14117

answered Oct 15 '14 at 7:27

pravin salame

23924

Swift 4.0

you create the Selector like below.

1.add the event to a button like:

button.addTarget(self, action: #selector(clickedButton(sender:)), for: UIControlEvents.touchUpInside)

and the function will be like below:

@objc func clickedButton(sender: AnyObject) {



}

share|improve this answer

edited Mar 15 at 17:50

Kevin Singh

14117

answered Oct 15 '14 at 7:27

pravin salame

23924

share|improve this answer

share|improve this answer

edited Mar 15 at 17:50

Kevin Singh

14117

edited Mar 15 at 17:50

Kevin Singh

14117

edited Mar 15 at 17:50

Kevin Singh

14117

14117

answered Oct 15 '14 at 7:27

pravin salame

23924

answered Oct 15 '14 at 7:27

pravin salame

23924

answered Oct 15 '14 at 7:27

pravin salame

23924

23924

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  You forgot to put @objc before func which is required in Swift 4.
  – Vahid Amiri
  Jan 27 at 15:49
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  You forgot to put @objc before func which is required in Swift 4.
  – Vahid Amiri
  Jan 27 at 15:49
  

  
  
  
  

3

3

You forgot to put @objc before func which is required in Swift 4.
– Vahid Amiri
Jan 27 at 15:49

You forgot to put @objc before func which is required in Swift 4.
– Vahid Amiri
Jan 27 at 15:49

add a comment | 

up vote
14
down vote

If you want to pass a parameter to the function from the NSTimer then here is your solution:

var somethingToPass = "It worked"



let timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "tester:", userInfo: somethingToPass, repeats: false)



func tester(timer: NSTimer)

{

    let theStringToPrint = timer.userInfo as String

    println(theStringToPrint)

}

Include the colon in the selector text (tester:), and your parameter(s) go in userInfo.

Your function should take NSTimer as a parameter. Then just extract userInfo to get the parameter that passed.

share|improve this answer

answered Aug 7 '14 at 15:29

Scooter

2,60212133

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
  – iOS-Coder
  Jul 5 '15 at 12:19
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
  – David Ganster
  Oct 5 '15 at 21:30
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
  – iOS-Coder
  Oct 6 '15 at 22:27
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
  – David Ganster
  Oct 7 '15 at 9:14
  

  
  
  
  

add a comment | 

up vote
14
down vote

If you want to pass a parameter to the function from the NSTimer then here is your solution:

var somethingToPass = "It worked"



let timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "tester:", userInfo: somethingToPass, repeats: false)



func tester(timer: NSTimer)

{

    let theStringToPrint = timer.userInfo as String

    println(theStringToPrint)

}

Include the colon in the selector text (tester:), and your parameter(s) go in userInfo.

Your function should take NSTimer as a parameter. Then just extract userInfo to get the parameter that passed.

share|improve this answer

answered Aug 7 '14 at 15:29

Scooter

2,60212133

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
  – iOS-Coder
  Jul 5 '15 at 12:19
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
  – David Ganster
  Oct 5 '15 at 21:30
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
  – iOS-Coder
  Oct 6 '15 at 22:27
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
  – David Ganster
  Oct 7 '15 at 9:14
  

  
  
  
  

add a comment | 

up vote
14
down vote

up vote
14
down vote

If you want to pass a parameter to the function from the NSTimer then here is your solution:

var somethingToPass = "It worked"



let timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "tester:", userInfo: somethingToPass, repeats: false)



func tester(timer: NSTimer)

{

    let theStringToPrint = timer.userInfo as String

    println(theStringToPrint)

}

Include the colon in the selector text (tester:), and your parameter(s) go in userInfo.

Your function should take NSTimer as a parameter. Then just extract userInfo to get the parameter that passed.

share|improve this answer

answered Aug 7 '14 at 15:29

Scooter

2,60212133

If you want to pass a parameter to the function from the NSTimer then here is your solution:

var somethingToPass = "It worked"



let timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: "tester:", userInfo: somethingToPass, repeats: false)



func tester(timer: NSTimer)

{

    let theStringToPrint = timer.userInfo as String

    println(theStringToPrint)

}

Include the colon in the selector text (tester:), and your parameter(s) go in userInfo.

Your function should take NSTimer as a parameter. Then just extract userInfo to get the parameter that passed.

share|improve this answer

answered Aug 7 '14 at 15:29

Scooter

2,60212133

share|improve this answer

share|improve this answer

answered Aug 7 '14 at 15:29

Scooter

2,60212133

answered Aug 7 '14 at 15:29

Scooter

2,60212133

answered Aug 7 '14 at 15:29

Scooter

2,60212133

2,60212133

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
  – iOS-Coder
  Jul 5 '15 at 12:19
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
  – David Ganster
  Oct 5 '15 at 21:30
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
  – iOS-Coder
  Oct 6 '15 at 22:27
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
  – David Ganster
  Oct 7 '15 at 9:14
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
  – iOS-Coder
  Jul 5 '15 at 12:19
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
  – David Ganster
  Oct 5 '15 at 21:30
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  @David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
  – iOS-Coder
  Oct 6 '15 at 22:27
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
  – David Ganster
  Oct 7 '15 at 9:14
  

  
  
  
  

3

3

I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
– iOS-Coder
Jul 5 '15 at 12:19

I was using NSTimer(0.01, target: self, ...) which did NOT work, whereas using NSTimer.scheduledTimerWithTimeInterval(0.01, ..) DID work!? Strange but thanks @Scooter for you answer!
– iOS-Coder
Jul 5 '15 at 12:19

1

1

@iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
– David Ganster
Oct 5 '15 at 21:30

@iOS-Coder just creating a timer with the initialiser does not add it to a runloop, whereas scheduledTimerWith... automatically adds it to the current runloop - so there is no strange behaviour here at all ;)
– David Ganster
Oct 5 '15 at 21:30

1

1

@David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
– iOS-Coder
Oct 6 '15 at 22:27

@David thanks for your suggestion. I guess my misunderstanding should belong in either STFW or RTFA (Read The F...ing API) category?
– iOS-Coder
Oct 6 '15 at 22:27

1

1

Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
– David Ganster
Oct 7 '15 at 9:14

Don't worry about it, no one can be expected to read the documentation about every single method in every API ;)
– David Ganster
Oct 7 '15 at 9:14

add a comment | 

up vote
10
down vote

Selectors are an internal representation of a method name in Objective-C. In Objective-C "@selector(methodName)" would convert a source-code method into a data type of SEL. Since you can't use the @selector syntax in Swift (rickster is on point there), you have to manually specify the method name as a String object directly, or by passing a String object to the Selector type. Here is an example:

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:"logout"

)

or

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:Selector("logout")

)

share|improve this answer

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

add a comment | 

up vote
10
down vote

Selectors are an internal representation of a method name in Objective-C. In Objective-C "@selector(methodName)" would convert a source-code method into a data type of SEL. Since you can't use the @selector syntax in Swift (rickster is on point there), you have to manually specify the method name as a String object directly, or by passing a String object to the Selector type. Here is an example:

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:"logout"

)

or

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:Selector("logout")

)

share|improve this answer

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

add a comment | 

up vote
10
down vote

up vote
10
down vote

Selectors are an internal representation of a method name in Objective-C. In Objective-C "@selector(methodName)" would convert a source-code method into a data type of SEL. Since you can't use the @selector syntax in Swift (rickster is on point there), you have to manually specify the method name as a String object directly, or by passing a String object to the Selector type. Here is an example:

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:"logout"

)

or

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:Selector("logout")

)

share|improve this answer

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

Selectors are an internal representation of a method name in Objective-C. In Objective-C "@selector(methodName)" would convert a source-code method into a data type of SEL. Since you can't use the @selector syntax in Swift (rickster is on point there), you have to manually specify the method name as a String object directly, or by passing a String object to the Selector type. Here is an example:

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:"logout"

)

or

var rightBarButton = UIBarButtonItem(

    title: "Logout", 

    style: UIBarButtonItemStyle.Plain, 

    target: self, 

    action:Selector("logout")

)

share|improve this answer

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

share|improve this answer

share|improve this answer

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

answered Jun 5 '14 at 5:43

Jon Tsiros

398114

398114

add a comment | 

add a comment | 

up vote
8
down vote

Swift 4.1

With sample of tap gesture

let gestureRecognizer = UITapGestureRecognizer()

self.view.addGestureRecognizer(gestureRecognizer)

gestureRecognizer.addTarget(self, action: #selector(self.dismiss(completion:)))



// Use destination 'Class Name' directly, if you selector (function) is not in same class.

//gestureRecognizer.addTarget(self, action: #selector(DestinationClass.dismiss(completion:)))





@objc func dismiss(completion: (() -> Void)?) {

      self.dismiss(animated: true, completion: completion)

}

See Apple's document for more details about: Selector Expression

share|improve this answer

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
  – Fogmeister
  Jun 9 '17 at 13:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
  – Krunal
  Jun 9 '17 at 13:59
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
  – Fogmeister
  Jun 9 '17 at 14:00
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Also, which part of this is different from Swift 3?
  – Fogmeister
  Jun 9 '17 at 14:02
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
  – Unome
  Sep 26 '17 at 15:33
  
  
  

  
  
  
  

 | 
show 1 more comment

up vote
8
down vote

Swift 4.1

With sample of tap gesture

let gestureRecognizer = UITapGestureRecognizer()

self.view.addGestureRecognizer(gestureRecognizer)

gestureRecognizer.addTarget(self, action: #selector(self.dismiss(completion:)))



// Use destination 'Class Name' directly, if you selector (function) is not in same class.

//gestureRecognizer.addTarget(self, action: #selector(DestinationClass.dismiss(completion:)))





@objc func dismiss(completion: (() -> Void)?) {

      self.dismiss(animated: true, completion: completion)

}

See Apple's document for more details about: Selector Expression

share|improve this answer

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
  – Fogmeister
  Jun 9 '17 at 13:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
  – Krunal
  Jun 9 '17 at 13:59
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
  – Fogmeister
  Jun 9 '17 at 14:00
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Also, which part of this is different from Swift 3?
  – Fogmeister
  Jun 9 '17 at 14:02
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
  – Unome
  Sep 26 '17 at 15:33
  
  
  

  
  
  
  

 | 
show 1 more comment

up vote
8
down vote

up vote
8
down vote

Swift 4.1

With sample of tap gesture

let gestureRecognizer = UITapGestureRecognizer()

self.view.addGestureRecognizer(gestureRecognizer)

gestureRecognizer.addTarget(self, action: #selector(self.dismiss(completion:)))



// Use destination 'Class Name' directly, if you selector (function) is not in same class.

//gestureRecognizer.addTarget(self, action: #selector(DestinationClass.dismiss(completion:)))





@objc func dismiss(completion: (() -> Void)?) {

      self.dismiss(animated: true, completion: completion)

}

See Apple's document for more details about: Selector Expression

share|improve this answer

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

Swift 4.1

With sample of tap gesture

let gestureRecognizer = UITapGestureRecognizer()

self.view.addGestureRecognizer(gestureRecognizer)

gestureRecognizer.addTarget(self, action: #selector(self.dismiss(completion:)))



// Use destination 'Class Name' directly, if you selector (function) is not in same class.

//gestureRecognizer.addTarget(self, action: #selector(DestinationClass.dismiss(completion:)))





@objc func dismiss(completion: (() -> Void)?) {

      self.dismiss(animated: true, completion: completion)

}

See Apple's document for more details about: Selector Expression

share|improve this answer

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

share|improve this answer

share|improve this answer

edited Apr 17 at 10:18

edited Apr 17 at 10:18

edited Apr 17 at 10:18

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

answered Jun 9 '17 at 13:43

Krunal

35.8k20130157

35.8k20130157

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
  – Fogmeister
  Jun 9 '17 at 13:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
  – Krunal
  Jun 9 '17 at 13:59
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
  – Fogmeister
  Jun 9 '17 at 14:00
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Also, which part of this is different from Swift 3?
  – Fogmeister
  Jun 9 '17 at 14:02
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
  – Unome
  Sep 26 '17 at 15:33
  
  
  

  
  
  
  

 | 
show 1 more comment

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
  – Fogmeister
  Jun 9 '17 at 13:58
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
  – Krunal
  Jun 9 '17 at 13:59
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
  – Fogmeister
  Jun 9 '17 at 14:00
  
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Also, which part of this is different from Swift 3?
  – Fogmeister
  Jun 9 '17 at 14:02
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
  – Unome
  Sep 26 '17 at 15:33
  
  
  

  
  
  
  

Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
– Fogmeister
Jun 9 '17 at 13:58

Please stop doing this. It helps no one. How is this any different from Swift 3.1? And why did you think it necessary to add another answer to this when it already has about 20 answers?
– Fogmeister
Jun 9 '17 at 13:58

calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
– Krunal
Jun 9 '17 at 13:59

calling selector is different in swift 4. Try these answers in swift 4 and see. None these will work without editing. Please do not mark any statement as spam without ensuring its impotance
– Krunal
Jun 9 '17 at 13:59

So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
– Fogmeister
Jun 9 '17 at 14:00

So is there any reason you couldn't edit the existing, accepted answer? It would make it actually useful rather than adding on the end of a long list of answers. The "Edit" button is there for a reason.
– Fogmeister
Jun 9 '17 at 14:00

Also, which part of this is different from Swift 3?
– Fogmeister
Jun 9 '17 at 14:02

Also, which part of this is different from Swift 3?
– Fogmeister
Jun 9 '17 at 14:02

2

2

You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
– Unome
Sep 26 '17 at 15:33

You have to add the objc tag to any selectors for Swift 4. This is the correct answer. And your not supposed to edit other people's answers to change their meaning. @Krunal is totally right.
– Unome
Sep 26 '17 at 15:33

 | 
show 1 more comment

up vote
6
down vote

// for swift 2.2

// version 1

buttton.addTarget(self, action: #selector(ViewController.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(ViewController.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 2

buttton.addTarget(self, action: #selector(self.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(self.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 3

buttton.addTarget(self, action: #selector(tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(tappedButton2(_:)), forControlEvents: .TouchUpInside)



func tappedButton() {

  print("tapped")

}



func tappedButton2(sender: UIButton) {

  print("tapped 2")

}



// swift 3.x

button.addTarget(self, action: #selector(tappedButton(_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton) {

  // tapped

}



button.addTarget(self, action: #selector(tappedButton(_:_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton, _ event: UIEvent) {

  // tapped

}

share|improve this answer

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

9615

• 
  
  
  

  
  

  
  
  
  
  
  

  
  it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
  – nyxee
  Jul 19 '17 at 22:24
  
  
  

  
  
  
  

add a comment | 

up vote
6
down vote

// for swift 2.2

// version 1

buttton.addTarget(self, action: #selector(ViewController.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(ViewController.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 2

buttton.addTarget(self, action: #selector(self.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(self.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 3

buttton.addTarget(self, action: #selector(tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(tappedButton2(_:)), forControlEvents: .TouchUpInside)



func tappedButton() {

  print("tapped")

}



func tappedButton2(sender: UIButton) {

  print("tapped 2")

}



// swift 3.x

button.addTarget(self, action: #selector(tappedButton(_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton) {

  // tapped

}



button.addTarget(self, action: #selector(tappedButton(_:_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton, _ event: UIEvent) {

  // tapped

}

share|improve this answer

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

9615

• 
  
  
  

  
  

  
  
  
  
  
  

  
  it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
  – nyxee
  Jul 19 '17 at 22:24
  
  
  

  
  
  
  

add a comment | 

up vote
6
down vote

up vote
6
down vote

// for swift 2.2

// version 1

buttton.addTarget(self, action: #selector(ViewController.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(ViewController.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 2

buttton.addTarget(self, action: #selector(self.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(self.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 3

buttton.addTarget(self, action: #selector(tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(tappedButton2(_:)), forControlEvents: .TouchUpInside)



func tappedButton() {

  print("tapped")

}



func tappedButton2(sender: UIButton) {

  print("tapped 2")

}



// swift 3.x

button.addTarget(self, action: #selector(tappedButton(_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton) {

  // tapped

}



button.addTarget(self, action: #selector(tappedButton(_:_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton, _ event: UIEvent) {

  // tapped

}

share|improve this answer

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

9615

// for swift 2.2

// version 1

buttton.addTarget(self, action: #selector(ViewController.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(ViewController.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 2

buttton.addTarget(self, action: #selector(self.tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(self.tappedButton2(_:)), forControlEvents: .TouchUpInside)



// version 3

buttton.addTarget(self, action: #selector(tappedButton), forControlEvents: .TouchUpInside)

buttton.addTarget(self, action: #selector(tappedButton2(_:)), forControlEvents: .TouchUpInside)



func tappedButton() {

  print("tapped")

}



func tappedButton2(sender: UIButton) {

  print("tapped 2")

}



// swift 3.x

button.addTarget(self, action: #selector(tappedButton(_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton) {

  // tapped

}



button.addTarget(self, action: #selector(tappedButton(_:_:)), for: .touchUpInside)



func tappedButton(_ sender: UIButton, _ event: UIEvent) {

  // tapped

}

share|improve this answer

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

9615

share|improve this answer

share|improve this answer

edited Jul 28 '17 at 6:01

edited Jul 28 '17 at 6:01

edited Jul 28 '17 at 6:01

answered Jun 1 '16 at 3:42

John Lee

9615

answered Jun 1 '16 at 3:42

John Lee

9615

answered Jun 1 '16 at 3:42

John Lee

9615

9615

• 
  
  
  

  
  

  
  
  
  
  
  

  
  it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
  – nyxee
  Jul 19 '17 at 22:24
  
  
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
  – nyxee
  Jul 19 '17 at 22:24
  
  
  

  
  
  
  

it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
– nyxee
Jul 19 '17 at 22:24

it would have been nicer and more educative if u had an example taking two or three arguments for Swift3 or Swift4 too. Thanks.
– nyxee
Jul 19 '17 at 22:24

add a comment | 

up vote
5
down vote

Create Refresh control using Selector method.   

    var refreshCntrl : UIRefreshControl!

    refreshCntrl = UIRefreshControl()

    refreshCntrl.tintColor = UIColor.whiteColor()

    refreshCntrl.attributedTitle = NSAttributedString(string: "Please Wait...")

    refreshCntrl.addTarget(self, action:"refreshControlValueChanged", forControlEvents: UIControlEvents.ValueChanged)

    atableView.addSubview(refreshCntrl)

//Refresh Control Method

func refreshControlValueChanged(){

    atableView.reloadData()

    refreshCntrl.endRefreshing()



}

share|improve this answer

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

add a comment | 

up vote
5
down vote

Create Refresh control using Selector method.   

    var refreshCntrl : UIRefreshControl!

    refreshCntrl = UIRefreshControl()

    refreshCntrl.tintColor = UIColor.whiteColor()

    refreshCntrl.attributedTitle = NSAttributedString(string: "Please Wait...")

    refreshCntrl.addTarget(self, action:"refreshControlValueChanged", forControlEvents: UIControlEvents.ValueChanged)

    atableView.addSubview(refreshCntrl)

//Refresh Control Method

func refreshControlValueChanged(){

    atableView.reloadData()

    refreshCntrl.endRefreshing()



}

share|improve this answer

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

add a comment | 

up vote
5
down vote

up vote
5
down vote

Create Refresh control using Selector method.   

    var refreshCntrl : UIRefreshControl!

    refreshCntrl = UIRefreshControl()

    refreshCntrl.tintColor = UIColor.whiteColor()

    refreshCntrl.attributedTitle = NSAttributedString(string: "Please Wait...")

    refreshCntrl.addTarget(self, action:"refreshControlValueChanged", forControlEvents: UIControlEvents.ValueChanged)

    atableView.addSubview(refreshCntrl)

//Refresh Control Method

func refreshControlValueChanged(){

    atableView.reloadData()

    refreshCntrl.endRefreshing()



}

share|improve this answer

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

Create Refresh control using Selector method.   

    var refreshCntrl : UIRefreshControl!

    refreshCntrl = UIRefreshControl()

    refreshCntrl.tintColor = UIColor.whiteColor()

    refreshCntrl.attributedTitle = NSAttributedString(string: "Please Wait...")

    refreshCntrl.addTarget(self, action:"refreshControlValueChanged", forControlEvents: UIControlEvents.ValueChanged)

    atableView.addSubview(refreshCntrl)

//Refresh Control Method

func refreshControlValueChanged(){

    atableView.reloadData()

    refreshCntrl.endRefreshing()



}

share|improve this answer

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

share|improve this answer

share|improve this answer

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

answered Jul 19 '14 at 6:26

Renish Dadhaniya

8,35722143

8,35722143

add a comment | 

add a comment | 

up vote
5
down vote

Since Swift 3.0 is published, it is even a little bit more subtle to declare a targetAction appropriate

class MyCustomView : UIView {



    func addTapGestureRecognizer() {



        // the "_" is important

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyCustomView.handleTapGesture(_:)))

        tapGestureRecognizer.numberOfTapsRequired = 1

        addGestureRecognizer(tapGestureRecognizer)

    }



    // since Swift 3.0 this "_" in the method implementation is very important to 

    // let the selector understand the targetAction

    func handleTapGesture(_ tapGesture : UITapGestureRecognizer) {



        if tapGesture.state == .ended {

            print("TapGesture detected")

        }

    }

}

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

add a comment | 

up vote
5
down vote

Since Swift 3.0 is published, it is even a little bit more subtle to declare a targetAction appropriate

class MyCustomView : UIView {



    func addTapGestureRecognizer() {



        // the "_" is important

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyCustomView.handleTapGesture(_:)))

        tapGestureRecognizer.numberOfTapsRequired = 1

        addGestureRecognizer(tapGestureRecognizer)

    }



    // since Swift 3.0 this "_" in the method implementation is very important to 

    // let the selector understand the targetAction

    func handleTapGesture(_ tapGesture : UITapGestureRecognizer) {



        if tapGesture.state == .ended {

            print("TapGesture detected")

        }

    }

}

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

add a comment | 

up vote
5
down vote

up vote
5
down vote

Since Swift 3.0 is published, it is even a little bit more subtle to declare a targetAction appropriate

class MyCustomView : UIView {



    func addTapGestureRecognizer() {



        // the "_" is important

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyCustomView.handleTapGesture(_:)))

        tapGestureRecognizer.numberOfTapsRequired = 1

        addGestureRecognizer(tapGestureRecognizer)

    }



    // since Swift 3.0 this "_" in the method implementation is very important to 

    // let the selector understand the targetAction

    func handleTapGesture(_ tapGesture : UITapGestureRecognizer) {



        if tapGesture.state == .ended {

            print("TapGesture detected")

        }

    }

}

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

Since Swift 3.0 is published, it is even a little bit more subtle to declare a targetAction appropriate

class MyCustomView : UIView {



    func addTapGestureRecognizer() {



        // the "_" is important

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(MyCustomView.handleTapGesture(_:)))

        tapGestureRecognizer.numberOfTapsRequired = 1

        addGestureRecognizer(tapGestureRecognizer)

    }



    // since Swift 3.0 this "_" in the method implementation is very important to 

    // let the selector understand the targetAction

    func handleTapGesture(_ tapGesture : UITapGestureRecognizer) {



        if tapGesture.state == .ended {

            print("TapGesture detected")

        }

    }

}

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

share|improve this answer

share|improve this answer

edited Nov 20 '16 at 0:17

Suragch

189k113655716

edited Nov 20 '16 at 0:17

Suragch

189k113655716

edited Nov 20 '16 at 0:17

Suragch

189k113655716

189k113655716

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

answered Sep 16 '16 at 18:24

LukeSideWalker

3,89911523

3,89911523

add a comment | 

add a comment | 

up vote
4
down vote

When using performSelector()

/addtarget()/NStimer.scheduledTimerWithInterval() methods your method (matching the selector) should be marked as

@objc

For Swift 2.0:

    {  

        //...

        self.performSelector(“performMethod”, withObject: nil , afterDelay: 0.5)

        //...





    //...

    btnHome.addTarget(self, action: “buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

    //...



    //...

     NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector : “timerMethod”, userInfo: nil, repeats: false)

    //...



}



@objc private func performMethod() {

…

}

@objc private func buttonPressed(sender:UIButton){

….

}

@objc private func timerMethod () {

….

}

For Swift 2.2,
you need to write '#selector()' instead of string and selector name so the possibilities of spelling error and crash due to that will not be there anymore. Below is example

self.performSelector(#selector(MyClass.performMethod), withObject: nil , afterDelay: 0.5)

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

add a comment | 

up vote
4
down vote

When using performSelector()

/addtarget()/NStimer.scheduledTimerWithInterval() methods your method (matching the selector) should be marked as

@objc

For Swift 2.0:

    {  

        //...

        self.performSelector(“performMethod”, withObject: nil , afterDelay: 0.5)

        //...





    //...

    btnHome.addTarget(self, action: “buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

    //...



    //...

     NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector : “timerMethod”, userInfo: nil, repeats: false)

    //...



}



@objc private func performMethod() {

…

}

@objc private func buttonPressed(sender:UIButton){

….

}

@objc private func timerMethod () {

….

}

For Swift 2.2,
you need to write '#selector()' instead of string and selector name so the possibilities of spelling error and crash due to that will not be there anymore. Below is example

self.performSelector(#selector(MyClass.performMethod), withObject: nil , afterDelay: 0.5)

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

add a comment | 

up vote
4
down vote

up vote
4
down vote

When using performSelector()

/addtarget()/NStimer.scheduledTimerWithInterval() methods your method (matching the selector) should be marked as

@objc

For Swift 2.0:

    {  

        //...

        self.performSelector(“performMethod”, withObject: nil , afterDelay: 0.5)

        //...





    //...

    btnHome.addTarget(self, action: “buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

    //...



    //...

     NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector : “timerMethod”, userInfo: nil, repeats: false)

    //...



}



@objc private func performMethod() {

…

}

@objc private func buttonPressed(sender:UIButton){

….

}

@objc private func timerMethod () {

….

}

For Swift 2.2,
you need to write '#selector()' instead of string and selector name so the possibilities of spelling error and crash due to that will not be there anymore. Below is example

self.performSelector(#selector(MyClass.performMethod), withObject: nil , afterDelay: 0.5)

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

When using performSelector()

/addtarget()/NStimer.scheduledTimerWithInterval() methods your method (matching the selector) should be marked as

@objc

For Swift 2.0:

    {  

        //...

        self.performSelector(“performMethod”, withObject: nil , afterDelay: 0.5)

        //...





    //...

    btnHome.addTarget(self, action: “buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

    //...



    //...

     NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector : “timerMethod”, userInfo: nil, repeats: false)

    //...



}



@objc private func performMethod() {

…

}

@objc private func buttonPressed(sender:UIButton){

….

}

@objc private func timerMethod () {

….

}

For Swift 2.2,
you need to write '#selector()' instead of string and selector name so the possibilities of spelling error and crash due to that will not be there anymore. Below is example

self.performSelector(#selector(MyClass.performMethod), withObject: nil , afterDelay: 0.5)

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

share|improve this answer

share|improve this answer

edited Jun 1 '16 at 11:59

Patrick

1,13531334

edited Jun 1 '16 at 11:59

Patrick

1,13531334

edited Jun 1 '16 at 11:59

Patrick

1,13531334

1,13531334

answered Mar 17 '16 at 6:48

sschunara

2,0451327

answered Mar 17 '16 at 6:48

sschunara

2,0451327

answered Mar 17 '16 at 6:48

sschunara

2,0451327

2,0451327

add a comment | 

add a comment | 

up vote
3
down vote

you create the Selector like below.

1.

UIBarButtonItem(

    title: "Some Title",

    style: UIBarButtonItemStyle.Done,

    target: self,

    action: "flatButtonPressed"

)

2.

flatButton.addTarget(self, action: "flatButtonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

Take note that the @selector syntax is gone and replaced with a simple String naming the method to call. There’s one area where we can all agree the verbosity got in the way. Of course, if we declared that there is a target method called flatButtonPressed: we better write one:

func flatButtonPressed(sender: AnyObject) {

  NSLog("flatButtonPressed")

}

set the timer:

    var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 

                    target: self, 

                    selector: Selector("flatButtonPressed"), 

                    userInfo: userInfo, 

                    repeats: true)

    let mainLoop = NSRunLoop.mainRunLoop()  //1

    mainLoop.addTimer(timer, forMode: NSDefaultRunLoopMode) //2 this two line is optinal

In order to be complete, here’s the flatButtonPressed

func flatButtonPressed(timer: NSTimer) {

}

share|improve this answer

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Do you have any source for "Take note that the @selector syntax is gone"?
  – winklerrr
  Mar 21 at 15:58
  

  
  
  
  

add a comment | 

up vote
3
down vote

you create the Selector like below.

1.

UIBarButtonItem(

    title: "Some Title",

    style: UIBarButtonItemStyle.Done,

    target: self,

    action: "flatButtonPressed"

)

2.

flatButton.addTarget(self, action: "flatButtonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

Take note that the @selector syntax is gone and replaced with a simple String naming the method to call. There’s one area where we can all agree the verbosity got in the way. Of course, if we declared that there is a target method called flatButtonPressed: we better write one:

func flatButtonPressed(sender: AnyObject) {

  NSLog("flatButtonPressed")

}

set the timer:

    var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 

                    target: self, 

                    selector: Selector("flatButtonPressed"), 

                    userInfo: userInfo, 

                    repeats: true)

    let mainLoop = NSRunLoop.mainRunLoop()  //1

    mainLoop.addTimer(timer, forMode: NSDefaultRunLoopMode) //2 this two line is optinal

In order to be complete, here’s the flatButtonPressed

func flatButtonPressed(timer: NSTimer) {

}

share|improve this answer

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Do you have any source for "Take note that the @selector syntax is gone"?
  – winklerrr
  Mar 21 at 15:58
  

  
  
  
  

add a comment | 

up vote
3
down vote

up vote
3
down vote

you create the Selector like below.

1.

UIBarButtonItem(

    title: "Some Title",

    style: UIBarButtonItemStyle.Done,

    target: self,

    action: "flatButtonPressed"

)

2.

flatButton.addTarget(self, action: "flatButtonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

Take note that the @selector syntax is gone and replaced with a simple String naming the method to call. There’s one area where we can all agree the verbosity got in the way. Of course, if we declared that there is a target method called flatButtonPressed: we better write one:

func flatButtonPressed(sender: AnyObject) {

  NSLog("flatButtonPressed")

}

set the timer:

    var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 

                    target: self, 

                    selector: Selector("flatButtonPressed"), 

                    userInfo: userInfo, 

                    repeats: true)

    let mainLoop = NSRunLoop.mainRunLoop()  //1

    mainLoop.addTimer(timer, forMode: NSDefaultRunLoopMode) //2 this two line is optinal

In order to be complete, here’s the flatButtonPressed

func flatButtonPressed(timer: NSTimer) {

}

share|improve this answer

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

you create the Selector like below.

1.

UIBarButtonItem(

    title: "Some Title",

    style: UIBarButtonItemStyle.Done,

    target: self,

    action: "flatButtonPressed"

)

2.

flatButton.addTarget(self, action: "flatButtonPressed:", forControlEvents: UIControlEvents.TouchUpInside)

Take note that the @selector syntax is gone and replaced with a simple String naming the method to call. There’s one area where we can all agree the verbosity got in the way. Of course, if we declared that there is a target method called flatButtonPressed: we better write one:

func flatButtonPressed(sender: AnyObject) {

  NSLog("flatButtonPressed")

}

set the timer:

    var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 

                    target: self, 

                    selector: Selector("flatButtonPressed"), 

                    userInfo: userInfo, 

                    repeats: true)

    let mainLoop = NSRunLoop.mainRunLoop()  //1

    mainLoop.addTimer(timer, forMode: NSDefaultRunLoopMode) //2 this two line is optinal

In order to be complete, here’s the flatButtonPressed

func flatButtonPressed(timer: NSTimer) {

}

share|improve this answer

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

share|improve this answer

share|improve this answer

edited Jul 11 '14 at 19:20

edited Jul 11 '14 at 19:20

edited Jul 11 '14 at 19:20

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

answered Jul 11 '14 at 19:14

Daxesh Nagar

1,2401020

1,2401020

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Do you have any source for "Take note that the @selector syntax is gone"?
  – winklerrr
  Mar 21 at 15:58
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Do you have any source for "Take note that the @selector syntax is gone"?
  – winklerrr
  Mar 21 at 15:58
  

  
  
  
  

Do you have any source for "Take note that the @selector syntax is gone"?
– winklerrr
Mar 21 at 15:58

Do you have any source for "Take note that the @selector syntax is gone"?
– winklerrr
Mar 21 at 15:58

add a comment | 

up vote
3
down vote

I found many of these answers to be helpful but it wasn't clear how to do this with something that wasn't a button. I was adding a gesture recognizer to a UILabel in swift and struggled so here's what I found worked for me after reading everything above:

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: "labelTapped:")

Where the "Selector" was declared as:

func labelTapped(sender: UILabel) { }

Note that it is public and that I am not using the Selector() syntax but it is possible to do this as well.

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: Selector("labelTapped:"))

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

add a comment | 

up vote
3
down vote

I found many of these answers to be helpful but it wasn't clear how to do this with something that wasn't a button. I was adding a gesture recognizer to a UILabel in swift and struggled so here's what I found worked for me after reading everything above:

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: "labelTapped:")

Where the "Selector" was declared as:

func labelTapped(sender: UILabel) { }

Note that it is public and that I am not using the Selector() syntax but it is possible to do this as well.

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: Selector("labelTapped:"))

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

add a comment | 

up vote
3
down vote

up vote
3
down vote

I found many of these answers to be helpful but it wasn't clear how to do this with something that wasn't a button. I was adding a gesture recognizer to a UILabel in swift and struggled so here's what I found worked for me after reading everything above:

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: "labelTapped:")

Where the "Selector" was declared as:

func labelTapped(sender: UILabel) { }

Note that it is public and that I am not using the Selector() syntax but it is possible to do this as well.

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: Selector("labelTapped:"))

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

I found many of these answers to be helpful but it wasn't clear how to do this with something that wasn't a button. I was adding a gesture recognizer to a UILabel in swift and struggled so here's what I found worked for me after reading everything above:

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: "labelTapped:")

Where the "Selector" was declared as:

func labelTapped(sender: UILabel) { }

Note that it is public and that I am not using the Selector() syntax but it is possible to do this as well.

let tapRecognizer = UITapGestureRecognizer(

            target: self,

            action: Selector("labelTapped:"))

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

share|improve this answer

share|improve this answer

answered Feb 14 '16 at 17:58

cynistersix

83011426

answered Feb 14 '16 at 17:58

cynistersix

83011426

answered Feb 14 '16 at 17:58

cynistersix

83011426

83011426

add a comment | 

add a comment | 

up vote
3
down vote

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.

override func viewDidLoad() {

        super.viewDidLoad()



        navigationItem.rightBarButtonItem =

            UIBarButtonItem(barButtonSystemItem: .Add, target: self,

                            action: #selector(addNewFireflyRefernce))

    }



    func addNewFireflyReference() {

        gratuitousReferences.append("Curse your sudden but inevitable betrayal!")

    }

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

add a comment | 

up vote
3
down vote

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.

override func viewDidLoad() {

        super.viewDidLoad()



        navigationItem.rightBarButtonItem =

            UIBarButtonItem(barButtonSystemItem: .Add, target: self,

                            action: #selector(addNewFireflyRefernce))

    }



    func addNewFireflyReference() {

        gratuitousReferences.append("Curse your sudden but inevitable betrayal!")

    }

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

add a comment | 

up vote
3
down vote

up vote
3
down vote

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.

override func viewDidLoad() {

        super.viewDidLoad()



        navigationItem.rightBarButtonItem =

            UIBarButtonItem(barButtonSystemItem: .Add, target: self,

                            action: #selector(addNewFireflyRefernce))

    }



    func addNewFireflyReference() {

        gratuitousReferences.append("Curse your sudden but inevitable betrayal!")

    }

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

Using #selector will check your code at compile time to make sure the method you want to call actually exists. Even better, if the method doesn’t exist, you’ll get a compile error: Xcode will refuse to build your app, thus banishing to oblivion another possible source of bugs.

override func viewDidLoad() {

        super.viewDidLoad()



        navigationItem.rightBarButtonItem =

            UIBarButtonItem(barButtonSystemItem: .Add, target: self,

                            action: #selector(addNewFireflyRefernce))

    }



    func addNewFireflyReference() {

        gratuitousReferences.append("Curse your sudden but inevitable betrayal!")

    }

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

share|improve this answer

share|improve this answer

answered May 20 '16 at 11:31

Swift Developer

357114

answered May 20 '16 at 11:31

Swift Developer

357114

answered May 20 '16 at 11:31

Swift Developer

357114

357114

add a comment | 

add a comment | 

up vote
2
down vote

It may be useful to note where you setup the control that triggers the action matters.

For example, I have found that when setting up a UIBarButtonItem, I had to create the button within viewDidLoad or else I would get an unrecognized selector exception.

override func viewDidLoad() {

        super.viewDidLoad()





        // add button

        let addButton = UIBarButtonItem(image: UIImage(named: "746-plus-circle.png"), style: UIBarButtonItemStyle.Plain, target: self, action: Selector("addAction:"))

        self.navigationItem.rightBarButtonItem = addButton

    }





    func addAction(send: AnyObject?) {



        NSLog("addAction")

    }

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

add a comment | 

up vote
2
down vote

It may be useful to note where you setup the control that triggers the action matters.

For example, I have found that when setting up a UIBarButtonItem, I had to create the button within viewDidLoad or else I would get an unrecognized selector exception.

override func viewDidLoad() {

        super.viewDidLoad()





        // add button

        let addButton = UIBarButtonItem(image: UIImage(named: "746-plus-circle.png"), style: UIBarButtonItemStyle.Plain, target: self, action: Selector("addAction:"))

        self.navigationItem.rightBarButtonItem = addButton

    }





    func addAction(send: AnyObject?) {



        NSLog("addAction")

    }

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

add a comment | 

up vote
2
down vote

up vote
2
down vote

It may be useful to note where you setup the control that triggers the action matters.

For example, I have found that when setting up a UIBarButtonItem, I had to create the button within viewDidLoad or else I would get an unrecognized selector exception.

override func viewDidLoad() {

        super.viewDidLoad()





        // add button

        let addButton = UIBarButtonItem(image: UIImage(named: "746-plus-circle.png"), style: UIBarButtonItemStyle.Plain, target: self, action: Selector("addAction:"))

        self.navigationItem.rightBarButtonItem = addButton

    }





    func addAction(send: AnyObject?) {



        NSLog("addAction")

    }

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

It may be useful to note where you setup the control that triggers the action matters.

For example, I have found that when setting up a UIBarButtonItem, I had to create the button within viewDidLoad or else I would get an unrecognized selector exception.

override func viewDidLoad() {

        super.viewDidLoad()





        // add button

        let addButton = UIBarButtonItem(image: UIImage(named: "746-plus-circle.png"), style: UIBarButtonItemStyle.Plain, target: self, action: Selector("addAction:"))

        self.navigationItem.rightBarButtonItem = addButton

    }





    func addAction(send: AnyObject?) {



        NSLog("addAction")

    }

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

share|improve this answer

share|improve this answer

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

answered Jul 12 '14 at 19:33

Michael Peterson

6,42713742

6,42713742

add a comment | 

add a comment | 

up vote
1
down vote

Change as a simple string naming in the method calling for selector syntax

var timer1 : NSTimer? = nil

timer1= NSTimer(timeInterval: 0.1, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

After that, type func test().

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

add a comment | 

up vote
1
down vote

Change as a simple string naming in the method calling for selector syntax

var timer1 : NSTimer? = nil

timer1= NSTimer(timeInterval: 0.1, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

After that, type func test().

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

add a comment | 

up vote
1
down vote

up vote
1
down vote

Change as a simple string naming in the method calling for selector syntax

var timer1 : NSTimer? = nil

timer1= NSTimer(timeInterval: 0.1, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

After that, type func test().

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

Change as a simple string naming in the method calling for selector syntax

var timer1 : NSTimer? = nil

timer1= NSTimer(timeInterval: 0.1, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

After that, type func test().

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

share|improve this answer

share|improve this answer

answered Oct 14 '14 at 4:49

Thar Htet

113

answered Oct 14 '14 at 4:49

Thar Htet

113

answered Oct 14 '14 at 4:49

Thar Htet

113

113

add a comment | 

add a comment | 

up vote
0
down vote

For swift 3

let timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.test), userInfo: nil, repeats: true)

Function Declaration In Same Class

func test()

{

    // my function

} 

share|improve this answer

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

add a comment | 

up vote
0
down vote

For swift 3

let timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.test), userInfo: nil, repeats: true)

Function Declaration In Same Class

func test()

{

    // my function

} 

share|improve this answer

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

add a comment | 

up vote
0
down vote

up vote
0
down vote

For swift 3

let timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.test), userInfo: nil, repeats: true)

Function Declaration In Same Class

func test()

{

    // my function

} 

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answered Feb 28 '17 at 6:41

Mustajab Jafry

639

For swift 3

let timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.test), userInfo: nil, repeats: true)

Function Declaration In Same Class

func test()

{

    // my function

} 

share|improve this answer

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

share|improve this answer

share|improve this answer

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

answered Feb 28 '17 at 6:41

Mustajab Jafry

639

639

add a comment | 

add a comment | 

up vote
0
down vote

For Swift 3

//Sample code to create timer

Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)



WHERE

timeInterval:- Interval in which timer should fire like 1s, 10s, 100s etc. [Its value is in secs]

target:- function which pointed to class. So here I am pointing to current class.

selector:- function that will execute when timer fires.



func updateTimer(){

    //Implemetation 

} 



repeats:- true/false specifies that timer should call again n again.

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answered May 19 at 17:03

CrazyPro007

785

add a comment | 

up vote
0
down vote

For Swift 3

//Sample code to create timer

Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)



WHERE

timeInterval:- Interval in which timer should fire like 1s, 10s, 100s etc. [Its value is in secs]

target:- function which pointed to class. So here I am pointing to current class.

selector:- function that will execute when timer fires.



func updateTimer(){

    //Implemetation 

} 



repeats:- true/false specifies that timer should call again n again.

share|improve this answer

answered May 19 at 17:03

CrazyPro007

785

add a comment | 

up vote
0
down vote

up vote
0
down vote

For Swift 3

//Sample code to create timer

Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)



WHERE

timeInterval:- Interval in which timer should fire like 1s, 10s, 100s etc. [Its value is in secs]

target:- function which pointed to class. So here I am pointing to current class.

selector:- function that will execute when timer fires.



func updateTimer(){

    //Implemetation 

} 



repeats:- true/false specifies that timer should call again n again.

share|improve this answer

answered May 19 at 17:03

CrazyPro007

785

For Swift 3

//Sample code to create timer

Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)



WHERE

timeInterval:- Interval in which timer should fire like 1s, 10s, 100s etc. [Its value is in secs]

target:- function which pointed to class. So here I am pointing to current class.

selector:- function that will execute when timer fires.



func updateTimer(){

    //Implemetation 

} 



repeats:- true/false specifies that timer should call again n again.

share|improve this answer

answered May 19 at 17:03

CrazyPro007

785

share|improve this answer

share|improve this answer

answered May 19 at 17:03

CrazyPro007

785

answered May 19 at 17:03

CrazyPro007

785

answered May 19 at 17:03

CrazyPro007

785

785

add a comment | 

add a comment | 

up vote
0
down vote

Selector in Swift 4:

button.addTarget(self, action: #selector(buttonTapped(sender:)), for: UIControlEvents.touchUpInside)

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edited yesterday

Moritz

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

add a comment | 

up vote
0
down vote

Selector in Swift 4:

button.addTarget(self, action: #selector(buttonTapped(sender:)), for: UIControlEvents.touchUpInside)

share|improve this answer

edited yesterday

Moritz

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

add a comment | 

up vote
0
down vote

up vote
0
down vote

Selector in Swift 4:

button.addTarget(self, action: #selector(buttonTapped(sender:)), for: UIControlEvents.touchUpInside)

share|improve this answer

edited yesterday

Moritz

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

Selector in Swift 4:

button.addTarget(self, action: #selector(buttonTapped(sender:)), for: UIControlEvents.touchUpInside)

share|improve this answer

edited yesterday

Moritz

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

share|improve this answer

share|improve this answer

edited yesterday

Moritz

56.9k19131184

edited yesterday

Moritz

56.9k19131184

edited yesterday

Moritz

56.9k19131184

56.9k19131184

answered yesterday

Mahesh Chaudhari

293

answered yesterday

Mahesh Chaudhari

293

answered yesterday

Mahesh Chaudhari

293

293

add a comment | 

add a comment | 

protected by Community♦ Mar 1 '15 at 21:02

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