Question

我不知道如何实现 RecyclerView 进行分段。首先，我开始解释我的代码。

public class HomeFragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_home, container, false);
    }
}

因此HomeFragment应该打开fragment_home.xml，看起来像这样...

    <androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".NoteActivity">

   <TextView
       android:id="@+id/textView4"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_marginTop="356dp"
       android:layout_marginEnd="152dp"
       android:text="Home fragment"
       android:textColor="#000000"
       app:layout_constraintEnd_toEndOf="parent"
       app:layout_constraintTop_toTopOf="parent" />

   <androidx.recyclerview.widget.RecyclerView
       android:id="@+id/recycler_view"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       tools:layout_editor_absoluteX="0dp"
       tools:layout_editor_absoluteY="16dp" />


</androidx.constraintlayout.widget.ConstraintLayout>

是的，它正在打开此布局 BUT ，而没有 RecyclerView （TextView正常）。我在想为什么会这样，我得出的结论是我必须在我的this class上实现HomeFragment（下图）（或者只是连接它，我又不知道怎么做）

public class NoteActivity extends AppCompatActivity {
    private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference notebookRef = db.collection("Notebook");

    private NoteAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_home);

        setUpRecyclerView();
    }

    public void setUpRecyclerView() {
        Query query = notebookRef.orderBy("title", Query.Direction.DESCENDING);

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

        adapter = new NoteAdapter(options);

        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
    }

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

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

请帮助，谢谢：）

如何实现RecyclerView到BottomNavigationBar的片段？

0 个答案: