FirebaseUI RecycleView 只显示第一项

Posted 2023-04-19

【中文标题】FirebaseUI RecycleView 只显示第一项

【英文标题】：FirebaseUI RecycleView only displays first item

【发布时间】：2021-02-13 10:05:15

【问题描述】：

我更新到 firebase-ui 6.3.0，它不再具有 populateViewHolder 方法。我根据我在网上找到的示例更改了代码。在我将 adapter.startListening() 添加到我的 home Activity 的 onStart 方法之前，RecycleView 没有显示任何内容。

问题是只显示 1 个项目，无法弄清楚原因。由于我使用 linearLayoutManager.setStackFromEnd(true) 显示的项目是最后一个项目，但是如果我注释掉该行，则显示第一个项目（并且上下文手册也不起作用）。

我检查了一些类似的 *** 问题，但找不到问题。

Firebase RecyclerView OnDataChanged only last element is Shown

Recycler View showing only very last item added to realtime database

这是我的类和 xml：

家庭活动：

    private RecyclerView transactionsRecyclerView;
    private TransactionRecordAdapter transactionRecordAdapter;

    private FirebaseHelper firebaseHelper;
    private Query query;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
 
        firebaseHelper = new FirebaseHelper();

        query = this.firebaseHelper.getTransactionRecordsOrderedByDateQuery();
        // FirebaseDatabase.getInstance().getReference().child(ConstantStringValue.DB_CHILD_TRANSACTION_RECORDS).child(auth.getCurrentUser().getUid())
        // .orderByChild("date");
        
        transactionsRecyclerView = findViewById(R.id.transactionsRecyclerView);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        linearLayoutManager.setReverseLayout(true);
        linearLayoutManager.setStackFromEnd(true);
        transactionsRecyclerView.setLayoutManager(linearLayoutManager);

        DividerItemDecoration itemDecoration = new DividerItemDecoration(this, VERTICAL);
        transactionsRecyclerView.addItemDecoration(itemDecoration);

        registerForContextMenu(transactionsRecyclerView);
    

    @Override
    protected void onStart() 
        super.onStart();
        transactionRecordAdapter = new TransactionRecordAdapter(TransactionRecord.class, query, this);
        transactionsRecyclerView.setAdapter(transactionRecordAdapter);
        transactionRecordAdapter.startListening();
    

    @Override
    protected void onStop() 
        super.onStop();
        transactionRecordAdapter.stopListening();
    

事务记录适配器：

    private int position;
    private String selectedItemId;
    private Context context;

    public TransactionRecordAdapter(Class<TransactionRecord> modelClass, Query ref, Context context) 
        super(new FirebaseRecyclerOptions.Builder<TransactionRecord>()
                .setQuery(ref, modelClass)
                .build());
        this.context = context;
     

    public int getPosition() 
        return position;
    

    public void setPosition(int position) 
        this.position = position;
    

    public String getSelectedItemId() 
        return selectedItemId;
    

    public void setSelectedItemId(String selectedItemId) 
        this.selectedItemId = selectedItemId;
    

    @Override
    protected void onBindViewHolder(@NonNull final TransactionRecordViewHolder holder, int position,
                                    @NonNull TransactionRecord model) 

         holder.itemView.setOnLongClickListener(v -> 
            setPosition(holder.getAdapterPosition());
            setSelectedItemId(holder.getId());
            return false;
        );

        holder.setAnnouncement(model.getAnnouncement());
        ...
        holder.setId(this.getRef(position).getKey());
    

    @NonNull
    @Override
    public TransactionRecordViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.transrecord, parent, false);
        return  new TransactionRecordViewHolder(view);
    

    @Override
    public void onViewRecycled(TransactionRecordViewHolder holder) 
        holder.itemView.setOnLongClickListener(null);
        super.onViewRecycled(holder);
    

TransactionRecordViewHolder：

    private View view;
    private String id;

    public TransactionRecordViewHolder(View itemView) 
        super(itemView);
        view = itemView;
        view.setOnCreateContextMenuListener(this);
    

    // ... setters

    public String getId() 
        return id;
    

    public void setId(String id) 
        this.id = id;
    

    @Override
    public void onCreateContextMenu(ContextMenu contextMenu, View view, ContextMenu.ContextMenuInfo contextMenuInfo) 
        contextMenu.add(Menu.NONE, R.id.editTransHomeContext,
                Menu.NONE, "Szerkesztés");
        contextMenu.add(Menu.NONE, R.id.deleteTransHomeContext,
                Menu.NONE, "Törlés");
    

activity_home.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context="hu.beczdev.cashbudget.activity.HomeActivity">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_
        android:layout_
        android:theme="@style/AppTheme.AppBarOverlay">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_
            android:layout_
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </com.google.android.material.appbar.AppBarLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:layout_
        android:layout_
        android:id="@+id/transactionsRecyclerView" />

</LinearLayout>

transrecord.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_
    android:layout_ >

        <TextView
            android:id="@+id/transAmountTextView"
            android:layout_
            android:layout_
            android:layout_alignParentStart="true"
            android:paddingStart="25dp"
            android:paddingTop="10dp"
            android:textSize="25sp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/transDateTextView"
            android:layout_
            android:layout_
            android:layout_alignParentEnd="true"
            android:paddingTop="10dp"
            android:paddingEnd="25dp"
            android:textSize="14sp" />

    <LinearLayout
        android:layout_
        android:layout_>

        <TextView
            android:layout_
            android:layout_
            android:textSize="18sp"
            android:paddingStart="25dp"
            android:textStyle="bold"
            android:id="@+id/transCatNameTextView"/>

    </LinearLayout>

    <LinearLayout
        android:layout_
        android:layout_>

        <TextView
            android:layout_
            android:layout_
            android:paddingBottom="10dp"
            android:textSize="15sp"
            android:paddingStart="25dp"
            android:id="@+id/transCommentView"/>

    </LinearLayout>

</LinearLayout>

【参考方案1】：

我认为你的问题不在firebase中，因为它已经返回了一行，你至少需要wrap_content列表项的高度才能不占据RecyclerView的整个高度。

所以在 transrecord.xml 中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_
    android:layout_ >

【讨论】：

这是一个很好的建议。我改变了高度，现在每个元素都是可见的。谢谢！