android - ReyclerView no funciona

android-recyclerview recycler-adapter

Question

Estoy tratando de mostrar la lista de mi modelo en la vista de reciclaje. pero por alguna razón no muestra nada. Recibo los elementos de mi lista de FirebaseDatabase y guardo todos los datos en "videoList". Entonces quiero presentar los datos que he recibido, pero no muestra nada.

Por favor dime que estoy haciendo mal.

  public class MyPlayListFragment extends Fragment {
    private FirebaseDatabase refToVideos;
    private FirebaseUser currentUser;
    private ArrayList<Video> videosList;
    private VideoViewAdapter adapter;
    private RecyclerView rvVideos;


public MyPlayListFragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_my_play_list, container, false);
    rvVideos = (RecyclerView)v.findViewById(R.id.rvVideos);

    return v;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    videosList = new ArrayList<>();
    refToVideos = FirebaseDatabase.getInstance();
    currentUser = FirebaseAuth.getInstance().getCurrentUser();

    refToVideos.getReference(Params.VIDEOS).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot snapshot : dataSnapshot.getChildren()){
                videosList.add(snapshot.getValue(Video.class));
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

    adapter = new VideoViewAdapter(getContext(),videosList);
    rvVideos.setLayoutManager(new LinearLayoutManager(getContext()));
    rvVideos.setAdapter(adapter);

}




public class VideoViewAdapter extends RecyclerView.Adapter<VideoViewHolder>{
  private LayoutInflater inflater;
  private Context context;
  private ArrayList<Video> data;

  public VideoViewAdapter( Context context, ArrayList<Video> data) {
      this.context = context;
      this.inflater = LayoutInflater.from(context);
      this.data = data;
  }

  @Override
  public VideoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
      View v = inflater.inflate(R.layout.video_item,parent,false);
      return new VideoViewHolder(v);
  }

  @Override
  public void onBindViewHolder(VideoViewHolder holder, int position) {
      Video video = data.get(position);
      holder.tvTitleVideo.setText(video.getVideoName());
      holder.tvLikes.setText(String.valueOf(video.getLikes()));
      holder.tvViews.setText(String.valueOf(video.getViews()));
      Uri uri = Uri.parse(video.getVideoURL());
      holder.videoViewUser.setVideoURI(uri);
      holder.videoViewUser.start();

  }

  @Override
  public int getItemCount() {
      return 0;
  }
}

public  class VideoViewHolder extends RecyclerView.ViewHolder{
    private TextView tvTitleVideo,tvLikes,tvViews;
    private VideoView videoViewUser;

    public VideoViewHolder(View itemView) {
        super(itemView);
        tvTitleVideo = (TextView) itemView.findViewById(R.id.videoTitle);
        tvLikes = (TextView)itemView.findViewById(R.id.tvLikes);
        tvViews = (TextView)itemView.findViewById(R.id.tvViews);
        videoViewUser = (VideoView)itemView.findViewById(R.id.videoViewUser);

      }
    }

 }

Answer 1

Debe return el size de su ArrayList de data en getItemCount()

Utilizar esta:

@Override
public int getItemCount() {
    return data.size();
}

En lugar de esto:

@Override
public int getItemCount() {
    return 0;
}

Answer 2

Estás usando el siguiente código

 @Override
 public int getItemCount() {
  return 0;
 }

Estás devolviendo cero. Esta es la razón por la que no se muestra nada. Necesita devolver el tamaño de la lista de datos. en su caso debe ser videosList.size ()

Answer 3

Por favor cambia tu código

getitemcount()
{
   return 0:
}

to 

videosList.size();



public class MyPlayListFragment extends Fragment {
    private FirebaseDatabase refToVideos;
    private FirebaseUser currentUser;
    private ArrayList<Video> videosList;
    private VideoViewAdapter adapter;
    private RecyclerView rvVideos;


public MyPlayListFragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_my_play_list, container, false);
    rvVideos = (RecyclerView)v.findViewById(R.id.rvVideos);

    return v;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    videosList = new ArrayList<>();
    refToVideos = FirebaseDatabase.getInstance();
    currentUser = FirebaseAuth.getInstance().getCurrentUser();

    refToVideos.getReference(Params.VIDEOS).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot snapshot : dataSnapshot.getChildren()){
                videosList.add(snapshot.getValue(Video.class));
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

    adapter = new VideoViewAdapter(getContext(),videosList);
    rvVideos.setLayoutManager(new LinearLayoutManager(getContext()));
    rvVideos.setAdapter(adapter);

}




public class VideoViewAdapter extends RecyclerView.Adapter<VideoViewHolder>{
  private LayoutInflater inflater;
  private Context context;
  private ArrayList<Video> data;

  public VideoViewAdapter( Context context, ArrayList<Video> data) {
      this.context = context;
      this.inflater = LayoutInflater.from(context);
      this.data = data;
  }

  @Override
  public VideoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
      View v = inflater.inflate(R.layout.video_item,parent,false);
      return new VideoViewHolder(v);
  }

  @Override
  public void onBindViewHolder(VideoViewHolder holder, int position) {
      Video video = data.get(position);
      holder.tvTitleVideo.setText(video.getVideoName());
      holder.tvLikes.setText(String.valueOf(video.getLikes()));
      holder.tvViews.setText(String.valueOf(video.getViews()));
      Uri uri = Uri.parse(video.getVideoURL());
      holder.videoViewUser.setVideoURI(uri);
      holder.videoViewUser.start();

  }

  @Override
  public int getItemCount() {
      return "YourList.size()";
  }
}

public  class VideoViewHolder extends RecyclerView.ViewHolder{
    private TextView tvTitleVideo,tvLikes,tvViews;
    private VideoView videoViewUser;

    public VideoViewHolder(View itemView) {
        super(itemView);
        tvTitleVideo = (TextView) itemView.findViewById(R.id.videoTitle);
        tvLikes = (TextView)itemView.findViewById(R.id.tvLikes);
        tvViews = (TextView)itemView.findViewById(R.id.tvViews);
        videoViewUser = (VideoView)itemView.findViewById(R.id.videoViewUser);

      }
    }

 }

Answer 4

Prueba esto

@Override
  public int getItemCount() {
      return data.size();
  }

Answer 5

Su VideoViewAdapter debe saber cuántos elementos debe mostrar, para eso necesita proporcionar el tamaño de su variable de data , a través del método getItemCount() :

@Override
public int getItemCount() {
    return data.size();
}

Answer 6

Su problema será resuelto.

Use este código en su adapter :

@Override
public int getItemCount() {
    return data.size();
}