Question

我正在尝试在recyclerview上显示我的模型列表。但由于某种原因，它没有显示任何东西。我从FirebaseDatabase获取列表项并将所有数据保存在“videoList”上。然后我想呈现我收到的数据，但它没有显示任何内容。

请告诉我我做错了什么。

  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

您应该return size data getItemCount() @Override public int getItemCount() { return data.size(); } @Override public int getItemCount() { return 0; } {{1}} {{1}}

使用此功能：

{{1}}

而不是：

{{1}}

Answer 2

试试这个

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

Answer 3

你的问题将得到解决。

在adapter：

中使用此代码

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

Answer 4

请更改您的代码

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 5

您正在使用以下代码

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

你回零。这就是没有显示任何内容的原因。您需要返回数据列表大小。在你的情况下，它应该是videosList.size（）

Answer 6

您的VideoViewAdapter应该知道他应该展示多少项目，为此您需要通过data方法提供getItemCount()变量的大小：

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

ReyclerView无法正常工作

6 个答案: