android - usar - son los elementos qué construyen un recyclerview

Error al utilizar RecyclerView: el elemento secundario especificado ya tiene un elemento primario

Question

Estoy tratando de crear un listView con un nuevo adaptador RecyvlerView. He seguido la guía exacta presente en los recursos para desarrolladores de Android. Pero esto me está dando un error extraño: el niño especificado ya tiene un padre. Primero debe llamar a removeView () en el padre del niño. Tengo el último SDK. También defino dependencias en gradle.

MyActivity (Actividad principal):

public class MyActivity extends Activity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
mRecyclerView.setHasFixedSize(true);
// use a linear layout manager
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
// specify an adapter (see also next example)
mAdapter = new MyAdapter(new String[]{"Zain", "Nadeem"});
mRecyclerView.setAdapter(mAdapter);
}
}

MyAdapter:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private String[] mDataset;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(String[] myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View v = inflater.inflate(R.layout.my_text_view, parent, true);
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mTextView.setText(mDataset[position]);
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
return mDataset.length;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView mTextView;
public ViewHolder(View v) {
super(v);
mTextView = (TextView) v.findViewById(R.id.item_title);
}
}
}

my_text_view.xml (diseño para elementos de la lista):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="80dp"
>
<!-- title -->
<TextView
android:id="@+id/item_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@android:color/darker_gray"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:textSize="22dp" />
</RelativeLayout>

activity_my.xml (actividad principal):

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:background="@android:color/holo_orange_light"
>
<!-- A CardView that contains a TextView -->
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycler_view"
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MyActivity"/>
</LinearLayout>

Y aquí está la salida de logcat:

10-28 01:20:30.287 22729-22729/osman.zaingz.com.lollipop E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: osman.zaingz.com.lollipop, PID: 22729
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child''s parent first.
at android.view.ViewGroup.addViewInner(ViewGroup.java:3562)
at android.view.ViewGroup.addView(ViewGroup.java:3415)
at android.view.ViewGroup.addView(ViewGroup.java:3360)
at android.support.v7.widget.RecyclerView$4.addView(RecyclerView.java:322)
at android.support.v7.widget.ChildHelper.addView(ChildHelper.java:79)
at android.support.v7.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:4845)
at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:4803)
at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:4791)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1316)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1265)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:522)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:1918)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:2155)
at android.view.View.layout(View.java:14817)
at android.view.ViewGroup.layout(ViewGroup.java:4631)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1660)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1436)
at android.view.View.layout(View.java:14817)
at android.view.ViewGroup.layout(ViewGroup.java:4631)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:14817)
at android.view.ViewGroup.layout(ViewGroup.java:4631)
at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
at android.view.View.layout(View.java:14817)
at android.view.ViewGroup.layout(ViewGroup.java:4631)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
at android.view.View.layout(View.java:14817)
at android.view.ViewGroup.layout(ViewGroup.java:4631)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1983)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1740)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:996)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5600)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
at android.view.Choreographer.doCallbacks(Choreographer.java:574)
at android.view.Choreographer.doFrame(Choreographer.java:544)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)

Answer 1

Lo resolví eliminando `TransitionManager.beginDelayedTransition ();

Answer 2

Tal vez sea un poco tarde, pero tuve el mismo problema (recyclerview-v7: 26.1.0) y la razón fue que intenté desplazar (mediante el método scrollToPosition ()) la lista en una posición que estaba actualmente visible. Después de agregar una comprobación de posición antes de desplazarme (desplazarse solo en la posición invisible), el problema se resolvió

Answer 3

También sucede si te desplazas muy rápido en tu vista de reciclador. Mi caso fue insertar / mover / ... elementos con DiffUtils y llamar a TransitionManager.beginDelayedTransition(view) en el diseño raíz (y, por lo tanto, la vista de reciclaje) en algún lugar de mi código antes del final de las animaciones de vista de reciclaje

Answer 4

al inflar no debe adjuntar la vista a su padre. tu escribiste:

View v = inflater.inflate(R.layout.my_text_view, parent, true);

que debería ser:

View v = inflater.inflate(R.layout.my_text_view, parent, false);

Answer 5

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="80dp">
<TextView
android:id="@+id/item_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@android:color/darker_gray"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:textSize="22dp" />
</RelativeLayout>

RelativeLayout esto es padre de su TextView con id item_title . Luego, cuando RecyclerView intenta agregar TextView que tiene padre, arroja una excepción.

Prueba este código:

public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
Log.d(TAG, "onCreateViewHolder");
RelativeLayout v = (RelativeLayout)LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
// set the view''s size, margins, paddings and layout parameters
View view = v.findViewById(R.id.text1);
v.removeView(view);
ViewHolder vh = new ViewHolder(view);
return vh;
}