java - E/RecyclerView 错误 : No adapter attached; skipping layout

Question

I want to get a list of registered users in UserFragment, actually here is my code, but when I go to the "Users" tab I get an error: E/RecyclerView: No adapter attached; skipping layout

UsersFragment.java

public class UsersFragment extends Fragment {


RecyclerView recyclerView;
AdapterUsers adapterUsers;
List<ModelUser> userList;

FirebaseAuth firebaseAuth;

public UsersFragment() {
}


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

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

    firebaseAuth = FirebaseAuth.getInstance();

    recyclerView = view.findViewById(R.id.users_recyclerView);

    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    userList = new ArrayList<>();

    getAllUsers();

    return view;
}

private void getAllUsers() {
    final FirebaseUser fUser = FirebaseAuth.getInstance().getCurrentUser();
    DatabaseReference ref = FirebaseDatabase.getInstance().getReference("users");
    ref.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            userList.clear();
            for (DataSnapshot ds: dataSnapshot.getChildren()){
                ModelUser modelUser = ds.getValue(ModelUser.class);

                if (!modelUser.getUid().equals(fUser.getUid())){
                    userList.add(modelUser);
                }

                adapterUsers = new AdapterUsers(getActivity(), userList);
                recyclerView.setAdapter(adapterUsers);

            }

        }

what am I doing wrong?

Answer 1

在构建用户列表后，在 for 循环之外执行此部分:

adapterUsers = new AdapterUsers(getActivity(), userList);
recyclerView.setAdapter(adapterUsers);

或者，在 onCreate 中，您可以使用空的 userList 设置回收器 View 的适配器，然后在 getAllUsers() 末尾设置 函数，并在 adapterUsers 中更新新的 userList，然后调用 notifyDataSetChanged()