android - RecyclerView:没有附加适配器；跳过布局

Question

我一直在 stackoverflow 和这个 blog post 上阅读不同的答案并尝试实现他们的解决方案，但我仍然遇到错误:

RecyclerView﹕ No adapter attached; skipping layout

所以我在 fragment 中的 onCreateView 中初始化我的回收器 View ，如下所示:

public class ProfileFragment extends Fragment {

private ModelUser user;

private View view;
private RecyclerView gridView;
private ProfilePhotoRecyclerViewAdapter adapter;
private List<ModelAttachment> photoList = new ArrayList<ModelAttachment>();

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.fragment_profile, container, false);

    initializeRecyclerView();

    //Get extra info for user
    QueryAPI query = new QueryAPI();
    query.userExtra(user, new QueryAPI.ApiResponse<ModelUser>() {
        @Override
        public void onCompletion(ModelUser result) {
            user = result;
                photoList.clear();
                photoList.addAll(0,user.getPhotos());

                adapter.notifyDataSetChanged();

            }
        });

     return view;

}

}

函数initializeRecyclerView:

void initializeRecyclerView() {
        gridView = (RecyclerView) view.findViewById(R.id.grid_view);
        StaggeredGridLayoutManager gridLayoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.HORIZONTAL );
        adapter = new ProfilePhotoRecyclerViewAdapter(getActivity(), photoList);
        gridView.setAdapter(adapter);
        gridView.setLayoutManager(gridLayoutManager);
        gridView.setHasFixedSize(true);
    }

fragment 中的布局:

 <android.support.v7.widget.RecyclerView
  android:id="@+id/grid_view"
  android:layout_width="match_parent"
  android:layout_height="match_parent"/>

以及项目的布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<com.android.volley.toolbox.NetworkImageView
    android:id="@+id/imageView"
    android:contentDescription="@string/image_description"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:scaleType="centerCrop"
    android:adjustViewBounds="true" />

 </LinearLayout>

我做错了什么？

编辑:这是适配器:

public class ProfilePhotoRecyclerViewAdapter extends  RecyclerView.Adapter<ProfilePhotoRecyclerViewAdapter.ViewHolder> {

    private LayoutInflater inflater;
    private List<ModelAttachment> photos; //data
    private Activity listContext;
    private int listRowLayoutId;
    ImageLoader imageLoader = AppController.getInstance().getImageLoader();


    public ProfilePhotoRecyclerViewAdapter(Activity context, List<ModelAttachment> objs) {
        photos = objs;
        listContext = context;
        this.notifyDataSetChanged();
    }

    @Override
    public ProfilePhotoRecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int i) {

        View itemView = LayoutInflater.from(listContext).inflate(R.layout.profile_photogrid_item, parent, false);

        return new ProfilePhotoRecyclerViewAdapter.ViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(ProfilePhotoRecyclerViewAdapter.ViewHolder viewHolder, int i) {

        ModelAttachment photo = photos.get(i);
        viewHolder.imageView.setImageUrl(photo.getUrl(), imageLoader);
    }

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


    public static class ViewHolder extends RecyclerView.ViewHolder {

        ModelAttachment photo;
        public NetworkImageView imageView;

        public ViewHolder(View itemView) {
            super(itemView);
            this.imageView = (NetworkImageView) itemView.findViewById(R.id.imageView);
        }
    }
}

Answer 1

我从来没有遇到过这个问题，对我来说真的很难复制。 😺

这是因为您没有先将空适配器设置为 RecyclerView。您提供的博客没有确切说明如何。这是我通常的写作方式。

我的适配器构造函数通常看起来像这样。

public ProfilePhotoRecyclerViewAdapter(Activity context) {
  photos = new ArrayList<>();
  listContext = context;
}

并为对象数组列表编写公共(public)(setter)方法。

public void setPhotos(List< ModelAttachment> photoList) {
  photos.clear();
  photos.addAll(photoList);
  this.notifyItemRangeInserted(0, photos.size() - 1);
}

并且在您的 fragment 中，您不必再使用照片数组进行初始化。

adapter = new ProfilePhotoRecyclerViewAdapter(getActivity());

只需在 API 响应的 onCompletion 方法中从适配器调用 setter 方法。

@Override
public void onCompletion(ModelUser result) {
  photoList.clear();
  photoList.addAll(0,user.getPhotos());

  adapter.setPhotos(photoList);
}

我认为这可能会解决。欢迎提问和讨论。

干杯，

上海