Mixing
Kotlin: How to call getSupportFragmentManager() in RecyclerView.Adapter
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I would like to call the Support Fragment Manager in my RecyclerView.Adapter after the click event in order to move to a different fragment. My approach:
(context as MainActivity).supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
But I get the following error:
kotlin.TypeCastException: null cannot be cast to non-null type
Can you help me?
android kotlin edited Jan 3 at 9:29
Lovis
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
add a comment |
I would like to call the Support Fragment Manager in my RecyclerView.Adapter after the click event in order to move to a different fragment. My approach:
(context as MainActivity).supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
But I get the following error:
kotlin.TypeCastException: null cannot be cast to non-null type
Can you help me?
android kotlin edited Jan 3 at 9:29
Lovis
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
contextis null, just make sure to set a value before casting it toMainActivity
– Omar Mainegra
Jan 2 at 16:55
It is aTypecast Exceptionand it is sayingcan not be cast to non-null typesomething which does not allow null you are passing null to it. In Kotlin you need to add?to make in nullable
– Murtaza Khursheed Hussain
Jan 3 at 9:36
add a comment |
I would like to call the Support Fragment Manager in my RecyclerView.Adapter after the click event in order to move to a different fragment. My approach:
(context as MainActivity).supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
But I get the following error:
kotlin.TypeCastException: null cannot be cast to non-null type
Can you help me?
android kotlin edited Jan 3 at 9:29
Lovis
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
I would like to call the Support Fragment Manager in my RecyclerView.Adapter after the click event in order to move to a different fragment. My approach:
(context as MainActivity).supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
But I get the following error:
kotlin.TypeCastException: null cannot be cast to non-null type
Can you help me?
android kotlin android kotlin edited Jan 3 at 9:29
Lovis
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
edited Jan 3 at 9:29
Lovis
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
edited Jan 3 at 9:29
Lovis
4,44522140
edited Jan 3 at 9:29
Lovis
4,44522140
edited Jan 3 at 9:29
Lovis
4,44522140
4,44522140
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
asked Jan 2 at 16:21
Simon GiesenSimon Giesen
195
195
contextis null, just make sure to set a value before casting it toMainActivity
– Omar Mainegra
Jan 2 at 16:55
It is aTypecast Exceptionand it is sayingcan not be cast to non-null typesomething which does not allow null you are passing null to it. In Kotlin you need to add?to make in nullable
– Murtaza Khursheed Hussain
Jan 3 at 9:36
add a comment |
contextis null, just make sure to set a value before casting it toMainActivity
– Omar Mainegra
Jan 2 at 16:55
It is aTypecast Exceptionand it is sayingcan not be cast to non-null typesomething which does not allow null you are passing null to it. In Kotlin you need to add?to make in nullable
– Murtaza Khursheed Hussain
Jan 3 at 9:36
context is null, just make sure to set a value before casting it to MainActivity – Omar Mainegra
Jan 2 at 16:55
context is null, just make sure to set a value before casting it to MainActivity – Omar Mainegra
Jan 2 at 16:55
It is a
Typecast Exception and it is saying can not be cast to non-null type something which does not allow null you are passing null to it. In Kotlin you need to add ? to make in nullable– Murtaza Khursheed Hussain
Jan 3 at 9:36
It is a
Typecast Exception and it is saying can not be cast to non-null type something which does not allow null you are passing null to it. In Kotlin you need to add ? to make in nullable– Murtaza Khursheed Hussain
Jan 3 at 9:36
add a comment |
3 Answers
3
active
oldest
votes
This is because your Context instance in the adapter is not guaranteed to be an Activity. It could potentially be a ContextWrapper holding the Activity as a base Context. Attempting to unwrap this would be fragile.
Instead, I would recommend that you define an interface in your adapter. From your Activity, provide an implementation of this interface to your adapter that will perform the FragmentTransaction. For example:
class MyAdapter : RecyclerView.Adapter<MyType> {
private var listener: (() -> Unit)? = null
fun setListener(listener: (() -> Unit)?) {
this.listener = listener
}
// wherever your onClick is handled:
listener?.invoke()
}
Then, in the Activity that's initializing MyAdapter:
myAdapter.setListener {
supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
}
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
add a comment |
I suggest you handle your fragment transaction in your fragment/activity. This would help you to have cleaner code and using context in fragment/activity is much easier. Try to define the interface between your adapter and fragment and call your interface method in the adapter and implement the interface in activity/fragment. There you can access context easily.
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
add a comment |
get the activity or fragment as argument in your adapter.
class ArticleAdapter(private val articleActivity: ArticleActivity, private val docs: List<ArticleResult.ArticleDoc>) : RecyclerView.Adapter<ArticleAdapter.Holder>() {
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): Holder = Holder(LayoutInflater.from(p0.context).inflate(R.layout.row_general2, p0, false))
override fun getItemCount(): Int = docs.size
override fun onBindViewHolder(holder: Holder, position: Int) {
articleActivity.supportFragmentManager
}
class Holder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val textViewTitleRow = itemView.findViewById<TextView>(R.id.textViewTitleRow)!!
val textView1Row = itemView.findViewById<TextView>(R.id.textView1Row)!!
val textView2Row = itemView.findViewById<TextView>(R.id.textView2Row)!!
val imageViewDownloadRow = itemView.findViewById<ImageView>(R.id.imageViewDownloadRow)!!
val textViewMoreRow = itemView.findViewById<TextView>(R.id.textViewMoreRow)!!
val imageViewBookRow = itemView.findViewById<ImageView>(R.id.imageViewBookRow)!!
}
}
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
This is because your Context instance in the adapter is not guaranteed to be an Activity. It could potentially be a ContextWrapper holding the Activity as a base Context. Attempting to unwrap this would be fragile.
Instead, I would recommend that you define an interface in your adapter. From your Activity, provide an implementation of this interface to your adapter that will perform the FragmentTransaction. For example:
class MyAdapter : RecyclerView.Adapter<MyType> {
private var listener: (() -> Unit)? = null
fun setListener(listener: (() -> Unit)?) {
this.listener = listener
}
// wherever your onClick is handled:
listener?.invoke()
}
Then, in the Activity that's initializing MyAdapter:
myAdapter.setListener {
supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
}
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
add a comment |
This is because your Context instance in the adapter is not guaranteed to be an Activity. It could potentially be a ContextWrapper holding the Activity as a base Context. Attempting to unwrap this would be fragile.
Instead, I would recommend that you define an interface in your adapter. From your Activity, provide an implementation of this interface to your adapter that will perform the FragmentTransaction. For example:
class MyAdapter : RecyclerView.Adapter<MyType> {
private var listener: (() -> Unit)? = null
fun setListener(listener: (() -> Unit)?) {
this.listener = listener
}
// wherever your onClick is handled:
listener?.invoke()
}
Then, in the Activity that's initializing MyAdapter:
myAdapter.setListener {
supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
}
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
add a comment |
This is because your Context instance in the adapter is not guaranteed to be an Activity. It could potentially be a ContextWrapper holding the Activity as a base Context. Attempting to unwrap this would be fragile.
Instead, I would recommend that you define an interface in your adapter. From your Activity, provide an implementation of this interface to your adapter that will perform the FragmentTransaction. For example:
class MyAdapter : RecyclerView.Adapter<MyType> {
private var listener: (() -> Unit)? = null
fun setListener(listener: (() -> Unit)?) {
this.listener = listener
}
// wherever your onClick is handled:
listener?.invoke()
}
Then, in the Activity that's initializing MyAdapter:
myAdapter.setListener {
supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
}
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
This is because your Context instance in the adapter is not guaranteed to be an Activity. It could potentially be a ContextWrapper holding the Activity as a base Context. Attempting to unwrap this would be fragile.
Instead, I would recommend that you define an interface in your adapter. From your Activity, provide an implementation of this interface to your adapter that will perform the FragmentTransaction. For example:
class MyAdapter : RecyclerView.Adapter<MyType> {
private var listener: (() -> Unit)? = null
fun setListener(listener: (() -> Unit)?) {
this.listener = listener
}
// wherever your onClick is handled:
listener?.invoke()
}
Then, in the Activity that's initializing MyAdapter:
myAdapter.setListener {
supportFragmentManager
.beginTransaction()
.replace(MainActivity.FRAGMENT_CONTAINER, TextScreen())
.commit()
}
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
answered Jan 2 at 17:26
kcoppockkcoppock
114k39226245
114k39226245
add a comment |
add a comment |
I suggest you handle your fragment transaction in your fragment/activity. This would help you to have cleaner code and using context in fragment/activity is much easier. Try to define the interface between your adapter and fragment and call your interface method in the adapter and implement the interface in activity/fragment. There you can access context easily.
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
add a comment |
I suggest you handle your fragment transaction in your fragment/activity. This would help you to have cleaner code and using context in fragment/activity is much easier. Try to define the interface between your adapter and fragment and call your interface method in the adapter and implement the interface in activity/fragment. There you can access context easily.
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
add a comment |
I suggest you handle your fragment transaction in your fragment/activity. This would help you to have cleaner code and using context in fragment/activity is much easier. Try to define the interface between your adapter and fragment and call your interface method in the adapter and implement the interface in activity/fragment. There you can access context easily.
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
I suggest you handle your fragment transaction in your fragment/activity. This would help you to have cleaner code and using context in fragment/activity is much easier. Try to define the interface between your adapter and fragment and call your interface method in the adapter and implement the interface in activity/fragment. There you can access context easily.
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
answered Jan 3 at 9:33
Ehsan MashhadiEhsan Mashhadi
783619
783619
add a comment |
add a comment |
get the activity or fragment as argument in your adapter.
class ArticleAdapter(private val articleActivity: ArticleActivity, private val docs: List<ArticleResult.ArticleDoc>) : RecyclerView.Adapter<ArticleAdapter.Holder>() {
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): Holder = Holder(LayoutInflater.from(p0.context).inflate(R.layout.row_general2, p0, false))
override fun getItemCount(): Int = docs.size
override fun onBindViewHolder(holder: Holder, position: Int) {
articleActivity.supportFragmentManager
}
class Holder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val textViewTitleRow = itemView.findViewById<TextView>(R.id.textViewTitleRow)!!
val textView1Row = itemView.findViewById<TextView>(R.id.textView1Row)!!
val textView2Row = itemView.findViewById<TextView>(R.id.textView2Row)!!
val imageViewDownloadRow = itemView.findViewById<ImageView>(R.id.imageViewDownloadRow)!!
val textViewMoreRow = itemView.findViewById<TextView>(R.id.textViewMoreRow)!!
val imageViewBookRow = itemView.findViewById<ImageView>(R.id.imageViewBookRow)!!
}
}
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
add a comment |
get the activity or fragment as argument in your adapter.
class ArticleAdapter(private val articleActivity: ArticleActivity, private val docs: List<ArticleResult.ArticleDoc>) : RecyclerView.Adapter<ArticleAdapter.Holder>() {
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): Holder = Holder(LayoutInflater.from(p0.context).inflate(R.layout.row_general2, p0, false))
override fun getItemCount(): Int = docs.size
override fun onBindViewHolder(holder: Holder, position: Int) {
articleActivity.supportFragmentManager
}
class Holder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val textViewTitleRow = itemView.findViewById<TextView>(R.id.textViewTitleRow)!!
val textView1Row = itemView.findViewById<TextView>(R.id.textView1Row)!!
val textView2Row = itemView.findViewById<TextView>(R.id.textView2Row)!!
val imageViewDownloadRow = itemView.findViewById<ImageView>(R.id.imageViewDownloadRow)!!
val textViewMoreRow = itemView.findViewById<TextView>(R.id.textViewMoreRow)!!
val imageViewBookRow = itemView.findViewById<ImageView>(R.id.imageViewBookRow)!!
}
}
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
add a comment |
get the activity or fragment as argument in your adapter.
class ArticleAdapter(private val articleActivity: ArticleActivity, private val docs: List<ArticleResult.ArticleDoc>) : RecyclerView.Adapter<ArticleAdapter.Holder>() {
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): Holder = Holder(LayoutInflater.from(p0.context).inflate(R.layout.row_general2, p0, false))
override fun getItemCount(): Int = docs.size
override fun onBindViewHolder(holder: Holder, position: Int) {
articleActivity.supportFragmentManager
}
class Holder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val textViewTitleRow = itemView.findViewById<TextView>(R.id.textViewTitleRow)!!
val textView1Row = itemView.findViewById<TextView>(R.id.textView1Row)!!
val textView2Row = itemView.findViewById<TextView>(R.id.textView2Row)!!
val imageViewDownloadRow = itemView.findViewById<ImageView>(R.id.imageViewDownloadRow)!!
val textViewMoreRow = itemView.findViewById<TextView>(R.id.textViewMoreRow)!!
val imageViewBookRow = itemView.findViewById<ImageView>(R.id.imageViewBookRow)!!
}
}
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
get the activity or fragment as argument in your adapter.
class ArticleAdapter(private val articleActivity: ArticleActivity, private val docs: List<ArticleResult.ArticleDoc>) : RecyclerView.Adapter<ArticleAdapter.Holder>() {
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): Holder = Holder(LayoutInflater.from(p0.context).inflate(R.layout.row_general2, p0, false))
override fun getItemCount(): Int = docs.size
override fun onBindViewHolder(holder: Holder, position: Int) {
articleActivity.supportFragmentManager
}
class Holder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val textViewTitleRow = itemView.findViewById<TextView>(R.id.textViewTitleRow)!!
val textView1Row = itemView.findViewById<TextView>(R.id.textView1Row)!!
val textView2Row = itemView.findViewById<TextView>(R.id.textView2Row)!!
val imageViewDownloadRow = itemView.findViewById<ImageView>(R.id.imageViewDownloadRow)!!
val textViewMoreRow = itemView.findViewById<TextView>(R.id.textViewMoreRow)!!
val imageViewBookRow = itemView.findViewById<ImageView>(R.id.imageViewBookRow)!!
}
}
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
answered Jan 3 at 9:57
SinaMN75SinaMN75
282411
282411
add a comment |
add a comment |
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contextis null, just make sure to set a value before casting it toMainActivity– Omar Mainegra
Jan 2 at 16:55
It is a
Typecast Exceptionand it is sayingcan not be cast to non-null typesomething which does not allow null you are passing null to it. In Kotlin you need to add?to make in nullable– Murtaza Khursheed Hussain
Jan 3 at 9:36