Recyclerview doesn’t show anything?… here is a solution to the problem.
Recyclerview doesn’t show anything?
I’m trying to display a list of strings in the Recycle Bin View. For some reason, it doesn’t work. It doesn’t show anything.
I don’t know why it doesn’t work, it’s not the first time I’ve used it, normally I do it with Firebase Recycler.
Here is my code
rvTypeMusic = (RecyclerView)findViewById(R.id.rvMusicType);
ArrayList<String> songs = new ArrayList<String>();
songs.add("PHP");
songs.add("C#");
songs.add("Java");
songs.add("JavaScript");
songs.add("Android");
adapter = new TypeMusicListAdapter(this,songs);
rvTypeMusic.setAdapter(adapter);
rvTypeMusic.setLayoutManager(new GridLayoutManager(this,2));
}
public static class TypeMusicListAdapter extends
RecyclerView.Adapter<TypeMusicListViewHolder>{
private LayoutInflater inflater;
private Context context;
private List<String> data;
public TypeMusicListAdapter(Context context, List<String> data){
this.context = context;
this.inflater = LayoutInflater.from(context);
this.data = data;
}
@Override
public TypeMusicListViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = inflater.inflate(R.layout.type_music_item,parent,false);
return new TypeMusicListViewHolder(v);
}
@Override
public void onBindViewHolder(TypeMusicListViewHolder holder, int position) {
String songType = data.get(position);
holder.musicType.setText(songType.getSongName());
holder.musicType.setText(songType);
}
@Override
public int getItemCount() {
return 0;
}
}
public static class TypeMusicListViewHolder extends RecyclerView.ViewHolder {
private TextView musicType;
public TypeMusicListViewHolder(View itemView) {
super(itemView);
musicType = (TextView) itemView.findViewById(R.id.musicType);
}
}
XML file
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.world.bolandian.talent.MainActivity"
tools:showIn="@layout/app_bar_main">
<android.support.v7.widget.RecyclerView
android:id="@+id/rvMusicType"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="0dp"
android:layout_marginLeft="0dp"
android:layout_marginRight="0dp"
android:layout_marginTop="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:listitem="@layout/type_music_item">
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
XML project
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView
android:id="@+id/musicType"
android:padding="25dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:textAppearance="@style/TextAppearance.AppCompat.Display1" />
</android.support.v7.widget.CardView>
</LinearLayout>
What am I missing here? I tried a few things but nothing worked.
Solution
The answer is a hybrid of @abdur Rahman and @ADM.
First, we have to set the layout manager to RecyclerView before setting up the adapter like this.
rvTypeMusic.setLayoutManager(new GridLayoutManager(this,2));
rvTypeMusic.setAdapter(adapter);
Because recycling a View will start placing the View as soon as we set up the adapter, it must have a layout manager by then.
second
This
@Override
public int getItemCount() {
return data.size();
}
onCreateViewHolder and onBindViewHolder are called only when a nonzero value is returned