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，这是我用来参考的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());
    }
}

除了启动上面的片段之外，我的MainActivity中没有任何内容。我不知道我的代码有什么问题。它显示没有错误，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textview字段进行检查以确定（现在已删除）。我希望你帮我解决问题。这可能是因为适配器？帮帮我搞清楚我还上传了我的数据库片段。提前致谢！

Answer 1

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();
}

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

Answer 2

创建如下所示的recyclerview：

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

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

2 个答案: