Question

我正在学习片段，我做了这个应用程序来显示食谱列表，这个列表的每一行都有食谱的图像和食谱的名称，我把recyclerView放在一个片段里，但问题是当我打开应用程序时，recyclelerView的内容变得混乱并在向下滚动后恢复正常，如下面的两个屏幕截图所示。

before scrolling

after scrolling down

MainActivity类

public class MainActivity extends AppCompatActivity {

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

    ListFragment listFragment = new ListFragment();
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.add(R.id.placeHolder, listFragment);
    fragmentTransaction.commit();
}}

ListAdapter类

public class ListAdapter extends RecyclerView.Adapter{
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item,parent,
            false);
    return new ListViewHolder(view);
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    ((ListViewHolder) holder).bindView(position);
}

@Override
public int getItemCount() {
    return Recipes.names.length;
}


private class ListViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
     private TextView mRecipeText;
     private ImageView mRecipeImage;
    public ListViewHolder(View itemView) {
        super(itemView);
        mRecipeImage = itemView.findViewById(R.id.itemImage);
        mRecipeText = itemView.findViewById(R.id.itemText);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {

    }

    public void bindView(int position) {
        mRecipeText.setText(Recipes.names[position]);
        mRecipeImage.setImageResource(Recipes.resourceIds[position]);
    }
}}

listFragment class

public class ListFragment extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_list, container , false);
    RecyclerView recyclerView = view.findViewById(R.id.listRecyclerView);
    ListAdapter listAdapter = new ListAdapter();
    recyclerView.setAdapter(listAdapter);
    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layoutManager);
    return view;
}}

activity_main.xml中

    <?xml version="1.0" encoding="utf-8"?>

<FrameLayout
    android:id="@+id/placeHolder"
    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="com.example.elswefi.smellslikebakin.MainActivity">
</FrameLayout>

fragment_list.xml

    <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/listRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

</android.support.constraint.ConstraintLayout>

list_item.xml

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:orientation="horizontal"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/itemImage"
        android:layout_width="0dp"
        android:layout_height="50dp"
        android:layout_weight="1"
        android:layout_margin="8dp"
        android:scaleType="fitCenter"
        app:srcCompat="@drawable/bagels"
        />

    <TextView
        android:id="@+id/itemText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:layout_margin="12dp"
        android:text="TextView"
        android:textSize="24sp"

        />
</LinearLayout>

我希望有人可以帮助我，因为我还在学习，我不知道这个bug来自哪里。

Answer 1

问题已解决

我通过添加这行代码解决了这个问题 android:adjustViewBounds="true" 到list_item.xml文件中的imageView

谢谢你们的评论，我真的很感激。

Android：当我打开应用程序时，RecyclerView内容搞砸了，向下滚动

1 个答案: