java - RecyclerView 不显示项目。不调用适配器

Question

所以我确定我在某个地方犯了一些微不足道的错误，只是看不到它。但我只是想创建一个基本的 recyclerview 列表。但是，当我运行该应用程序时，没有显示任何内容，我输入了日志语句，发现适配器已创建，但从未对其调用任何内容(如 bindviewholder、createviewholder 或 getItemsize)。我不确定发生了什么。代码如下”

主要 Activity :

public class MainActivity extends GvrActivity {
    private ArrayList<SampleItem> videos;
    private RecyclerView recyclerView;
    private SampleAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        intialization();

    }

    private void intialization() {
        Log.e("tree","mata intialized");
        videos = new ArrayList<>();
        videos.add(new SampleItem("http://vid1383.photobucket.com/albums/ah303/intellidev/congo_zpsrtmtey4l.mp4", "Adrian", 50, 100));
        Log.e("tree","video added");
        recyclerView = (RecyclerView) findViewById(R.id.recycle);
        adapter = new SampleAdapter(this, videos);
        recyclerView.setAdapter(adapter);
        Log.e("tree","intialization completed");
    }
}

适配器

public class SampleAdapter extends     RecyclerView.Adapter<SampleAdapter.ItemHolder> {
private Context context;
    private ArrayList<SampleItem> items;

    public SampleAdapter(Context context, ArrayList<SampleItem> videos) {

        this.context = context;
        this.items = videos;
        Log.e("tree","adapter created");
    }

    @Override
    public ItemHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.
                from(parent.getContext()).
                inflate(R.layout.video_item, parent, false);
        Log.e("tree","onCreateView Done");
        return new ItemHolder(itemView);
    }

    @Override
    public void onBindViewHolder(ItemHolder holder, int position) {
        Uri uri = Uri.parse(items.get(0).getVideoUrl());
        VrVideoView.Options options = new VrVideoView.Options();
        options.inputType = VrVideoView.Options.TYPE_STEREO_OVER_UNDER;
        try {
            holder.view.loadVideo(uri, options);
            holder.view.playVideo();
        } catch (IOException e) {
            Log.e("tree","onBindViewError " +e.getMessage());
        }
        holder.likes.setText(items.get(position).getNumOfLikes());
        holder.shares.setText(items.get(position).getNumOfShares());
        holder.profile.setText(items.get(position).getProfileName());
        Log.e("tree","onBindViewDone");

    }

    @Override
    public int getItemCount() {
        Log.e("tree","items size is "+items.size());
        return items.size();
    }

    class ItemHolder extends RecyclerView.ViewHolder {
        private VrVideoView view;
        private Button likes;
        private Button shares;
        private Button profile;

        public ItemHolder(View itemView) {
            // Stores the itemView in a public final member variable that can be used
            // to access the context from any ViewHolder instance.
            super(itemView);

            view = (VrVideoView) itemView.findViewById(R.id.video_view);
            likes = (Button) itemView.findViewById(R.id.likesButton);
            shares = (Button) itemView.findViewById(R.id.sharesButton);
            profile = (Button) itemView.findViewById(R.id.videoProfileButton);

        }

    }
}

Answer 1

如果你想使用 RecyclerView，你需要处理以下内容:

• RecyclerView.Adapter - 处理数据收集并将其绑定(bind)到 View

• LayoutManager - 帮助定位项目

• ItemAnimator - 帮助为常见操作设置项目动画例如项目的添加或删除

item animator 是可选的，但 adapter 和 Layoutmanager 是必需的

您忘记添加布局管理器。这两行代码可能解决了你的问题

LinearLayoutManager llm = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(llm);