RecyclerView 的 ItemDecoration 破坏了使用 ConstraintLayout 构建的项目布局

Question

我正在尝试构建这种布局 - 只有两列网格，图像下方有图像和文本。

我想使用 RecyclerView、GridLayoutManager 和 ItemDecoration 来构建项目之间的间距。这是我得到的结果，你可以看到右图下方的文字移到了底部。

MainActivity

public class MainActivity extends AppCompatActivity {

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

        RecyclerView recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);

        GridLayoutManager layoutManager = new GridLayoutManager(this, 2);
        recyclerView.setLayoutManager(layoutManager);

        recyclerView.addItemDecoration(new SpacesItemDecoration());

        Adapter adapter = new Adapter();
        recyclerView.setAdapter(adapter);
    }
}

SpacesItemDecoration

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {

    @Override
    public void getItemOffsets(Rect outRect, View view,
                               RecyclerView parent, RecyclerView.State state) {
        outRect.bottom = 20;

        if (parent.getChildLayoutPosition(view) % 2 == 0) {
            outRect.right = 20;
        } else {
            outRect.right = 0;
        }
    }
}

item.xml

<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="#DDDDDD"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/image_view"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:scaleType="centerCrop"
        app:layout_constraintDimensionRatio="h,4:5"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/text_view"
        app:layout_constraintVertical_chainStyle="packed" />

    <TextView
        android:id="@+id/text_view"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:textStyle="bold"
        android:gravity="center"
        app:layout_constraintTop_toBottomOf="@+id/image_view"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent" />

</android.support.constraint.ConstraintLayout>

你也可以从GitHub克隆项目

Answer 1

从您发布的屏幕截图来看，右侧的图像看起来比左侧的图像大，这就是将文本向下推到右侧的原因。这可能是由SpacesItemDecoration 定义插图的方式引起的。尝试更改左/右插图以平衡视图。

SpacesItemDecoration

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {

    @Override
    public void getItemOffsets(Rect outRect, View view,
                               RecyclerView parent, RecyclerView.State state) {
        outRect.bottom = 20;

        if (parent.getChildLayoutPosition(view) % 2 == 0) {
            outRect.right = 10; // Pad on the right for left-hand side
        } else {
            outRect.left = 10; // Pad on the left for right-hand side
        }
    }
}