在回收站视图android中回扫后无法清除部分滑动删除按钮答案

【问题标题】：Not able to clear the partial swipe delete button after swipe back in recycler view android在回收站视图android中回扫后无法清除部分滑动删除按钮
【发布时间】：2018-05-27 12:22:49
【问题描述】：

我正在尝试在我的应用中创建类似 gmail 滑动操作的存档。

我可以在滑动时绘制图像和文本。但问题是滑回后删除按钮图像没有被删除。

滑回后如何删除删除按钮。我不知道我的代码做错了什么。

class SwipeController extends Callback {

    private Paint p = new Paint();
    private Context context;
    public SwipeController(Context context) {
          this.context = context;
    }
    @Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        return makeMovementFlags(0, LEFT);
    }


    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        return false;
    }

    @Override
    public int convertToAbsoluteDirection(int flags, int layoutDirection) {
        Log.d("convertToDirection","convertToAbsoluteDirection Executed");
        return super.convertToAbsoluteDirection(flags, layoutDirection);
    }
    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
        int position = viewHolder.getAdapterPosition();

        if (direction == ItemTouchHelper.LEFT){
            //adapter.removeItem(position);remove item from adapter
        }
    }

    @Override
    public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {

        Bitmap icon;
        if(actionState == ItemTouchHelper.ACTION_STATE_SWIPE){

            View itemView = viewHolder.itemView;
            float height = (float) itemView.getBottom() - (float) itemView.getTop();
            float width = height / 3;


            try{
                if(dX > 0){
                    p.setColor(Color.parseColor("#388E3C"));
                    RectF background = new RectF((float) itemView.getLeft(), (float) itemView.getTop(), dX,(float) itemView.getBottom());
                    c.drawRect(background,p);
                    icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.voicemaildelte);
                    RectF icon_dest = new RectF((float) itemView.getLeft() + width ,(float) itemView.getTop() + width,(float) itemView.getLeft()+ 2*width,(float)itemView.getBottom() - width);
                    c.drawBitmap(icon,null,icon_dest,p);
                } else {
                    p.setColor(Color.parseColor("#D32F2F"));
                    RectF background = new RectF((float) itemView.getRight() + dX, (float) itemView.getTop(),(float) itemView.getRight(), (float) itemView.getBottom());
                    c.drawRect(background,p);
                    icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.voicemaildelte);
                    RectF icon_dest = new RectF((float) itemView.getRight() - 2*width ,(float) itemView.getTop() + width,(float) itemView.getRight() - width,(float)itemView.getBottom() - width);
                    c.drawBitmap(icon,null,icon_dest,p);
                }
            }catch(Exception e){
                e.printStackTrace();
            }

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


}

【问题讨论】：

标签： android android-recyclerview recyclerview-layout itemtouchhelper

【解决方案1】：

找到了重绘它们的方法。

isCurrentlyActive 此变量指示视图当前是否处于用户的控制之下，它返回 true，因此仅在用户滑动视图时使用它来绘制按钮。

@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {

    Bitmap icon;
    if(actionState == ItemTouchHelper.ACTION_STATE_SWIPE && isCurrentlyActive){

        View itemView = viewHolder.itemView;
        float height = (float) itemView.getBottom() - (float) itemView.getTop();
        float width = height / 3;


        try{
            if(dX > 0){
                p.setColor(Color.parseColor("#388E3C"));
                RectF background = new RectF((float) itemView.getLeft(), (float) itemView.getTop(), dX,(float) itemView.getBottom());
                c.drawRect(background,p);
                icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.voicemaildelte);
                RectF icon_dest = new RectF((float) itemView.getLeft() + width ,(float) itemView.getTop() + width,(float) itemView.getLeft()+ 2*width,(float)itemView.getBottom() - width);
                c.drawBitmap(icon,null,icon_dest,p);
            } else {
                p.setColor(Color.parseColor("#D32F2F"));
                RectF background = new RectF((float) itemView.getRight() + dX, (float) itemView.getTop(),(float) itemView.getRight(), (float) itemView.getBottom());
                c.drawRect(background,p);
                icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.voicemaildelte);
                RectF icon_dest = new RectF((float) itemView.getRight() - 2*width ,(float) itemView.getTop() + width,(float) itemView.getRight() - width,(float)itemView.getBottom() - width);
                c.drawBitmap(icon,null,icon_dest,p);
            }
        }catch(Exception e){
            e.printStackTrace();
        }

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

【讨论】：