android - RecyclerView ItemTouchHelper - 自定义 View

我正在尝试在向左/向右滑动时显示自定义视图（或图像）。
我已经接近让它工作了，但是我在使用自定义图像时遇到了问题。
我想要的效果与此类似：RecyclerView ItemTouchHelper swipe remove animation
看看下面发生了什么。它在刷卡时扭曲图像：

下面是我的代码：

@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder,
        float dX, float dY, int actionState, boolean isCurrentlyActive) {
    if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
        View itemView = viewHolder.itemView;

        Paint p = new Paint();
        if (dX > 0) {
            Drawable d = ContextCompat.getDrawable(getActivity(), R.drawable.test_check);
            d.setBounds(itemView.getLeft(), itemView.getTop(), (int) dX, itemView.getBottom());
            d.draw(c);

            super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
        }

        super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
    }
}

如何在继续绘制背景色时保持图像的静态？甚至可以使用android视图而不是图像吗？与此类似：https://github.com/wdullaer/SwipeActionAdapter

最佳答案

您可以准备Recycler视图项布局以包含复选标记ImageView，也可以准备另一个只有背景色的空白视图。您还应该将所有可滑动内容移动到嵌套布局中。为视图保持架中的可切换内容分配一个引用。然后在setTranslationX中的可滑动内容上调用onChildDraw，例如：

((MyViewHolder) viewHolder).swipeableContent.setTranslationX(dX);

用源代码更新示例：
回收器视图项布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="@dimen/recycler_view_item_height"
    android:background="@color/transparent">

    <!-- background color view -->
    <View
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/purple" />

    <!-- check symbol image view -->
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="@dimen/check_symbol_width"
        android:contentDescription="@null"
        android:src="@drawable/check_symbol" />

    <!-- swipeable content container -->
    <LinearLayout
        android:id="@+id/swipeable_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">
        <!-- here goes your swipeable content -->
    </LinearLayout>

</RelativeLayout>

视图保持器类：

class MyViewHolder extends RecyclerView.ViewHolder {

    // Swipeable content container.
    LinearLayout swipeableContent;

    /*
     ... here goes other sub-views
    */

    public ExpenseViewHolder(final View itemView) {
        super(itemView);
        // bind swipeable content container view
        swipeableContent = (LinearLayout) itemView.findViewById(R.id.swipeable_content);

        /*
         ... bind other sub-views
        */
    }
}

itemTouchhelper.callback子类：

class ItemTouchHelperCallback extends ItemTouchHelper.Callback {

    @Override
    public void onChildDraw(final Canvas c,
                            final RecyclerView recyclerView,
                            final RecyclerView.ViewHolder viewHolder,
                            final float dX,
                            final float dY,
                            final int actionState,
                            final boolean isCurrentlyActive) {
        if (viewHolder instanceof MyViewHolder) {
            // translate by swipe amount,
            // the check symbol and the background will stay in place
            ((MyViewHolder) viewHolder).swipeableContent.setTranslationX(dX);
        }
    }

}