使用 FirebaseUI 将 Firestore 放入 recyclerview，不显示任何数据

Question

我刚开始使用 Firestore。所以我尝试将我的数据直接拟合到 recyclerview 中，这里是我用作参考的 code。这是我的 UserRecyclerView 片段：

public class UserRecyclerView extends Fragment{
private ArrayList<User> user;
RecyclerView mRecyclerView;
public UserRecyclerView(){}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.recycler_view,container,false);
    mRecyclerView = (RecyclerView) view.findViewById(R.id.recycler_view);

    FirestoreRecyclerAdapter adapter = getFirestoreRecyclerAdapter();
    mRecyclerView.setAdapter(adapter);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

return view;
}

@NonNull
private FirestoreRecyclerAdapter getFirestoreRecyclerAdapter() {
    Query query = FirebaseFirestore.getInstance()
            .collection("users");

    FirestoreRecyclerOptions<User> options = new FirestoreRecyclerOptions.Builder<User>()
            .setQuery(query, User.class).build();

    return new FirestoreRecyclerAdapter<User, UserViewHolder>(options) {
        @Override
        protected void onBindViewHolder(UserViewHolder holder, int position, User model) {
            Log.d("USER", "DATA: "+model.getName());
            holder.BindView(position, model);

        }
        @Override
        public UserViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
           View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.users_list, parent, false);

            return new UserViewHolder(view);
        }
    };
}

private class UserViewHolder extends RecyclerView.ViewHolder{
    TextView info;
    UserViewHolder(View itemView) {
        super(itemView);
        info = (TextView) itemView.findViewById(R.id.info_text);
    }

    void BindView(int position, User model){

        info.setText(model.getName()+" , "+model.getId());
    }
}

除了启动上述片段外，我的 MainActivity 中没有任何内容。我不知道我的代码有什么问题。它没有显示任何错误，当我运行应用程序时它不会崩溃。它只是进入 recyclerview 布局，我通过放置一个 textview 字段来确定（现在删除）来检查它。我希望你帮我解决代码问题。应该是适配器的原因吧？帮我弄清楚。我还上传了我的数据库的一个片段。提前致谢！

Answer 1

像下面这样创建回收视图：

FirestoreRecyclerAdapter adapter = getFirestoreRecyclerAdapter();
//add below line
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setAdapter(adapter);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

Answer 2

确保在适配器上调用 startListening 以启动与 Cloud Firestore 的连接，否则将不会加载任何数据。

@Override
protected void onStart() {
    super.onStart();
    adapter.startListening();
}

@Override
protected void onStop() {
    super.onStop();
    adapter.stopListening();
}

参见： https://github.com/firebase/FirebaseUI-Android/blob/master/firestore/README.md#firestorerecycleradapter-lifecycle

使用 FirebaseUI 将 Firestore 放入 recyclerview，不显示任何数据

Firestore into recyclerview using FirebaseUI, no data displayed

firebase

android-recyclerview

firebaseui

google-cloud-firestore