RecyclerView 不顯示項目。 適配器未被調用

Question

所以我確定我在某處犯了一些小錯誤，只是看不到它。 但我只是想創建一個基本的 recyclerview 列表。 但是，當我運行應用程序時，什么也沒有顯示，我輸入了日志語句，發現適配器已創建，但從未調用過它（如 bindviewholder、createviewholder 或 getItemsize）。 我不確定發生了什么。 代碼在下面”

主要活動：

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");
    }
}

適配器

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

如果要使用RecyclerView ，則需要使用以下內容：

• RecyclerView.Adapter - 處理數據收集並將其綁定到視圖

• LayoutManager - 幫助定位項目

• ItemAnimator - 幫助為常見操作（例如添加或刪除項目）設置項目動畫

item animator 是可選的，但適配器和 Layoutmanager 是必需的

你忘了添加布局管理器。 這兩行代碼可能會解決您的問題

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

Answer 2

試試這個答案

https://stackoverflow.com/a/35802948/2144418

recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

Answer 3

添加

recyclerView.setLayoutManager(new LinearLayoutManager(context));

在回收者視圖初始化之后。 如果要使用項目網格，還可以設置 GridLayoutManager。