Continue a canceled task

Inside my code i'm using Sqlserver async.
If i will request CancellationTokenSource in my query i can't re use it in same Activity.
Example

  CancellationTokenSource cts; //Global 



 cts = new CancellationTokenSource();//OnCreate Method

BtnClik1

 using (SqlConnection connection = new SqlConnection(connectionString))

 using (SqlCommand cmd = new SqlCommand(query, connection))

 {

    await connection.OpenAsync(cts.Token);

    await cmd.ExecuteNonQueryAsync(cts.Token);

 }

BtnClick2

  if (cts.Token != null)

            cts.Cancel();

If i will press for some reson BtnClick2, then i cant re use BtnClick1, I'm taking error System Threadin tasks exception, A task was canceled

asked Nov 20 '18 at 7:06

ddd

357

1

After calling Cancel you will have to create a new instance and assign it to cts using cts = new CancellationTokenSource();

– Peter Bons
Nov 20 '18 at 7:09

Thank you ok, now i will understand my problem. Should i also dispose cts before creating a new one?

– ddd
Nov 20 '18 at 7:11

1

Yes, you should

– Peter Bons
Nov 20 '18 at 7:12

add a comment |

Inside my code i'm using Sqlserver async.
If i will request CancellationTokenSource in my query i can't re use it in same Activity.
Example

  CancellationTokenSource cts; //Global 



 cts = new CancellationTokenSource();//OnCreate Method

BtnClik1

 using (SqlConnection connection = new SqlConnection(connectionString))

 using (SqlCommand cmd = new SqlCommand(query, connection))

 {

    await connection.OpenAsync(cts.Token);

    await cmd.ExecuteNonQueryAsync(cts.Token);

 }

BtnClick2

  if (cts.Token != null)

            cts.Cancel();

If i will press for some reson BtnClick2, then i cant re use BtnClick1, I'm taking error System Threadin tasks exception, A task was canceled

asked Nov 20 '18 at 7:06

ddd

357

1

After calling Cancel you will have to create a new instance and assign it to cts using cts = new CancellationTokenSource();

– Peter Bons
Nov 20 '18 at 7:09

Thank you ok, now i will understand my problem. Should i also dispose cts before creating a new one?

– ddd
Nov 20 '18 at 7:11

1

Yes, you should

– Peter Bons
Nov 20 '18 at 7:12

add a comment |

Inside my code i'm using Sqlserver async.
If i will request CancellationTokenSource in my query i can't re use it in same Activity.
Example

  CancellationTokenSource cts; //Global 



 cts = new CancellationTokenSource();//OnCreate Method

BtnClik1

 using (SqlConnection connection = new SqlConnection(connectionString))

 using (SqlCommand cmd = new SqlCommand(query, connection))

 {

    await connection.OpenAsync(cts.Token);

    await cmd.ExecuteNonQueryAsync(cts.Token);

 }

BtnClick2

  if (cts.Token != null)

            cts.Cancel();

If i will press for some reson BtnClick2, then i cant re use BtnClick1, I'm taking error System Threadin tasks exception, A task was canceled

asked Nov 20 '18 at 7:06

ddd

357

Inside my code i'm using Sqlserver async.
If i will request CancellationTokenSource in my query i can't re use it in same Activity.
Example

  CancellationTokenSource cts; //Global 



 cts = new CancellationTokenSource();//OnCreate Method

BtnClik1

 using (SqlConnection connection = new SqlConnection(connectionString))

 using (SqlCommand cmd = new SqlCommand(query, connection))

 {

    await connection.OpenAsync(cts.Token);

    await cmd.ExecuteNonQueryAsync(cts.Token);

 }

BtnClick2

  if (cts.Token != null)

            cts.Cancel();

If i will press for some reson BtnClick2, then i cant re use BtnClick1, I'm taking error System Threadin tasks exception, A task was canceled

c# xamarin

asked Nov 20 '18 at 7:06

ddd

357

asked Nov 20 '18 at 7:06

ddd

357

asked Nov 20 '18 at 7:06

ddd

357

asked Nov 20 '18 at 7:06

ddd

357

asked Nov 20 '18 at 7:06

ddd

357

1

After calling Cancel you will have to create a new instance and assign it to cts using cts = new CancellationTokenSource();

– Peter Bons
Nov 20 '18 at 7:09

Thank you ok, now i will understand my problem. Should i also dispose cts before creating a new one?

– ddd
Nov 20 '18 at 7:11

1

Yes, you should

– Peter Bons
Nov 20 '18 at 7:12

add a comment |

1

After calling Cancel you will have to create a new instance and assign it to cts using cts = new CancellationTokenSource();

– Peter Bons
Nov 20 '18 at 7:09

Thank you ok, now i will understand my problem. Should i also dispose cts before creating a new one?

– ddd
Nov 20 '18 at 7:11

1

Yes, you should

– Peter Bons
Nov 20 '18 at 7:12

After calling Cancel you will have to create a new instance and assign it to cts using cts = new CancellationTokenSource();

– Peter Bons
Nov 20 '18 at 7:09

Thank you ok, now i will understand my problem. Should i also dispose cts before creating a new one?

– ddd
Nov 20 '18 at 7:11

Yes, you should

– Peter Bons
Nov 20 '18 at 7:12

add a comment |

1 Answer
1

active

oldest

votes

You could do something like this

private CancellationTokenSource _cts; 

private object syncObj = new Object();



public void BtnClik1(...)

{

   lock(syncObj)

   {

      _cts = _cts ?? new CancellationTokenSource();

   } 



   ...

}



public void BtnClik2(...)

{

   lock(syncObj)

   {

       cts?.Cancel();

       cts?.Dispose();

       cts = null; 

   } 

}

Note : the locking isn't really needed as there is probably bigger thread safety issues.

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

1

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

1

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

add a comment |

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

You could do something like this

private CancellationTokenSource _cts; 

private object syncObj = new Object();



public void BtnClik1(...)

{

   lock(syncObj)

   {

      _cts = _cts ?? new CancellationTokenSource();

   } 



   ...

}



public void BtnClik2(...)

{

   lock(syncObj)

   {

       cts?.Cancel();

       cts?.Dispose();

       cts = null; 

   } 

}

Note : the locking isn't really needed as there is probably bigger thread safety issues.

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

1

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

1

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

add a comment |

You could do something like this

private CancellationTokenSource _cts; 

private object syncObj = new Object();



public void BtnClik1(...)

{

   lock(syncObj)

   {

      _cts = _cts ?? new CancellationTokenSource();

   } 



   ...

}



public void BtnClik2(...)

{

   lock(syncObj)

   {

       cts?.Cancel();

       cts?.Dispose();

       cts = null; 

   } 

}

Note : the locking isn't really needed as there is probably bigger thread safety issues.

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

1

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

1

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

add a comment |

You could do something like this

private CancellationTokenSource _cts; 

private object syncObj = new Object();



public void BtnClik1(...)

{

   lock(syncObj)

   {

      _cts = _cts ?? new CancellationTokenSource();

   } 



   ...

}



public void BtnClik2(...)

{

   lock(syncObj)

   {

       cts?.Cancel();

       cts?.Dispose();

       cts = null; 

   } 

}

Note : the locking isn't really needed as there is probably bigger thread safety issues.

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

You could do something like this

private CancellationTokenSource _cts; 

private object syncObj = new Object();



public void BtnClik1(...)

{

   lock(syncObj)

   {

      _cts = _cts ?? new CancellationTokenSource();

   } 



   ...

}



public void BtnClik2(...)

{

   lock(syncObj)

   {

       cts?.Cancel();

       cts?.Dispose();

       cts = null; 

   } 

}

Note : the locking isn't really needed as there is probably bigger thread safety issues.

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

answered Nov 20 '18 at 7:11

TheGeneral

29.2k63365

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

1

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

1

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

add a comment |

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

1

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

1

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

What do i need to set it null? Dispose isn't the same?

– ddd
Nov 20 '18 at 7:19

@ddd So you don't use it again, its good practice

– TheGeneral
Nov 20 '18 at 7:19

One last question, doest Finish my activity disposes my CancellationTokenSource? Or i need to dispose it every time i close my activity?

– ddd
Nov 20 '18 at 7:25

@ddd it only needs to be disposed if it's been canceled. However if you form/activity what ever creates the cs goes out of scope you should dispose it

– TheGeneral
Nov 20 '18 at 7:29

add a comment |

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