@Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        if (recyclerView.getLayoutManager() instanceof GridLayoutManager) {
            final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
           //网格布局不处理滑动事件
            final int swipeFlags = 0;
        } else {
            final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
            //列表布局不处理滑动事件
            final int swipeFlags = 0; 
        }
        return makeMovementFlags(dragFlags, swipeFlags);
    }

@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
    int fromPosition = viewHolder.getAdapterPosition();
    int toPosition = target.getAdapterPosition();
    if (fromPosition < toPosition) {
        //分别把中间所有的item的位置重新交换
        for (int i = fromPosition; i < toPosition; i++) {
            Collections.swap(mData, i, i + 1);
        }
    } else {
        for (int i = fromPosition; i > toPosition; i--) {
            Collections.swap(mData, i, i - 1);
        }
    }
    //执行移动操作
    recyclerAdapter.notifyItemMoved(fromPosition, toPosition);
    return true;
}

@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
    int position = viewHolder.getAdapterPosition();
    //执行移除操作
    mData.remove(position);
    recyclerAdapter.notifyItemRemoved(position);
}

@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
    if(actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
        //滑动时改变Item的透明度
        final float alpha = 1 - Math.abs(dX) / (float)viewHolder.itemView.getWidth();
        viewHolder.itemView.setAlpha(alpha);
        viewHolder.itemView.setTranslationX(dX);
    }
}

 @Override
    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
            //选中item开始拖拽时，改变颜色
            viewHolder.itemView.setBackgroundColor(Color.blue);
        
    }

 @Override
 public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
     super.clearView(recyclerView, viewHolder);
     //拖拽或滑动完成时，变回白色
     viewHolder.itemView.setBackgroundColor(0);
 }

 @Override
 public boolean isLongPressDragEnabled() {
   return true;
 }