RecyclerView的ItemDecoration打破使用ConstraintLayout构建的项目布局

问题描述:

我试图构建这种布局 - 只有两列网格图像和图像下面的图像。RecyclerView的ItemDecoration打破使用ConstraintLayout构建的项目布局

Mockup

我想建立这种使用RecyclerView,GridLayoutManager和ItemDecoration为项目之间的间隔。这就是我得到的结果,因为您可以看到右侧图像下方的文字已移到底部。

Results

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> 

您可以从GitHub

从您发布的屏幕截图也克隆项目,它看起来像右边的图像比左边的图像大,这就是将文本向下向右。这可能是由SpacesItemDecoration如何定义插入引起的。尝试更改左/右插槽以平衡视图。

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 
     } 
    } 
}