Question

我在片段中使用了Recyclerview的firestore。但由于这个错误，我感到非常沮丧。 Recyclerview也未显示。当我们打开活动时，它显示为空白，活动中没有任何内容。（这种类型的问题已经被问到，但是我的问题有很多不同，比如我的代码非常不同，在那个问题中他能够看到Recyclerview而我不是。）

public class ForthFragment extends Fragment {

View myView;
private RecyclerView mMainList;
private FirebaseFirestore mFirestore;
private static final  String TAG = "FireLog";
private List<Users> usersList;
private UsersListAdapter usersListAdapter;
private Context applicationContext;


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    myView = inflater.inflate(R.layout.fragment_forth, container, false);

    mMainList = (RecyclerView) myView.findViewById(R.id.mainlist);
    mMainList.setHasFixedSize(true);
    mMainList.setLayoutManager(new LinearLayoutManager(this.getApplicationContext()));
    mMainList.setAdapter(usersListAdapter);
    onConencted();

    LinearLayoutManager llm = new LinearLayoutManager(this.getApplicationContext());

    mFirestore = FirebaseFirestore.getInstance();
    usersList = new ArrayList<>();
    usersListAdapter = new UsersListAdapter(usersList);

    mFirestore.collection("Users").addSnapshotListener(new EventListener<QuerySnapshot>() {
        @Override
        public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {

            if (e != null) {

                Log.d(TAG, "Error : " + e.getMessage());

            }
            for (DocumentChange doc : documentSnapshots.getDocumentChanges()) {

                if (doc.getType() == DocumentChange.Type.ADDED) {

                    Users users = doc.getDocument().toObject(Users.class);
                    usersList.add(users);
                    usersListAdapter.notifyDataSetChanged();


                }

            }

        }
    });


    return myView;
}

private void onConencted() {
    LinearLayoutManager llm = new LinearLayoutManager(this.getActivity());
    llm.setOrientation(LinearLayoutManager.VERTICAL);
    mMainList.setLayoutManager(llm);
    mMainList.setAdapter( usersListAdapter );
}


public Context getApplicationContext() {
    return applicationContext;
}

}

Answer 1

尝试使用以下代码：

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    myView = inflater.inflate(R.layout.fragment_forth, container, false);

    mMainList = (RecyclerView) myView.findViewById(R.id.mainlist);
    mMainList.setHasFixedSize(true);
    mMainList.setLayoutManager(new LinearLayoutManager(this.getApplicationContext()));

    onConencted();



    mFirestore = FirebaseFirestore.getInstance();
    usersList = new ArrayList<>();


    mFirestore.collection("Users").addSnapshotListener(new EventListener<QuerySnapshot>() {
        @Override
        public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {

            if (e != null) {

                Log.d(TAG, "Error : " + e.getMessage());

            }
            for (DocumentChange doc : documentSnapshots.getDocumentChanges()) {

                if (doc.getType() == DocumentChange.Type.ADDED) {

                    Users users = doc.getDocument().toObject(Users.class);
                    usersList.add(users);
                    usersListAdapter.notifyDataSetChanged();


                }

            }

        }
    });


    return myView;
}

private void onConencted() {
    LinearLayoutManager llm = new LinearLayoutManager(this.getActivity());
    llm.setOrientation(LinearLayoutManager.VERTICAL);
    mMainList.setLayoutManager(llm);
     usersListAdapter = new UsersListAdapter(usersList);
    mMainList.setAdapter( usersListAdapter );
}


public Context getApplicationContext() {
    return applicationContext;
}

Recyclerview没有适配器附加跳过布局片段

1 个答案: