ItemTouchHelper.Callback?mCallback?=?new?ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP|ItemTouchHelper.DOWN,ItemTouchHelper.RIGHT)?{ ? ??@Override ??public?boolean?onMove(RecyclerView?recyclerView,?RecyclerView.ViewHolder?viewHolder,?RecyclerView.ViewHolder?target)?{ ????int?fromPosition?=?viewHolder.getAdapterPosition();//得到拖動ViewHolder的position ????int?toPosition?=?target.getAdapterPosition();//得到目標ViewHolder的position ????if?(fromPosition?<?toPosition)?{ ??????//分別把中間所有的item的位置重新交換 ??????for?(int?i?=?fromPosition;?i?<?toPosition;?i++)?{ ????????Collections.swap(datas,?i,?i?+?1); ??????} ????}?else?{ ??????for?(int?i?=?fromPosition;?i?>?toPosition;?i--)?{ ????????Collections.swap(datas,?i,?i?-?1); ??????} ????} ????mAdapter.notifyItemMoved(fromPosition,?toPosition); ????//返回true表示執(zhí)行拖動 ????return?true; ??} ??@Override ??public?void?onSwiped(RecyclerView.ViewHolder?viewHolder,?int?direction)?{ ????int?position?=?viewHolder.getAdapterPosition(); ????datas.remove(position); ????mAdapter.notifyItemRemoved(position); ??} }; ItemTouchHelper?itemTouchHelper?=?new?ItemTouchHelper(mCallback); itemTouchHelper.attachToRecyclerView(mRecyclerView);拖拽上下滑動不了是怎么會事啊