RecyclerView Item上移下移侧滑删除

以前觉得item上移下移侧滑删除挺难的，也不好写直接用人家的轮子就好了，可是这几天看到别人写的这种效果，用RecyclerView来写也不是很难吗？

思路

RecyclerView有个工具类,ItemTouchHelper,借助这个工具类就可以实现上面全部的效果了，主要用到ItemTouchHelper.CallBall这个接口。这里有三个主要用到的重写方法onMovementFlage() 、onMove()、onSwiped()，具体用法看代码。

item布局

主要代码

 ItemTouchHelper.Callback callback = new ItemTouchHelper.Callback() {
      //判断手指滑动方向
        @Override
        public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            int drag = ItemTouchHelper.UP|ItemTouchHelper.DOWN;
            int swipe =ItemTouchHelper.LEFT|ItemTouchHelper.RIGHT;

            return makeMovementFlags(drag,swipe);

        }
      //上下移动Item
        @Override
        public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
          //判断移动的item和目的位置是不是同种item
            if(viewHolder.getItemViewType() != target.getItemViewType())
            {
                return false;
            }
            ((MyViewHolder)viewHolder).ivDown.setVisibility(View.GONE);
            adapter.onItemMove(viewHolder.getAdapterPosition(),target.getAdapterPosition());
            return true;
        }
      //左右滑动item
        @Override
        public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {

            ((MyViewHolder)viewHolder).ivDown.setVisibility(View.VISIBLE);
            adapter.onItemSwipe(viewHolder.getAdapterPosition());

        }
      //选择一个item
        @Override
        public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {

            if(viewHolder != null)
            {
              getDefaultUIUtil().onSelected(((MyViewHolder)viewHolder).llitem);

            }

        }
      //重绘item，在item下面
        @Override
        public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {

            getDefaultUIUtil().onDraw(c,recyclerView,((MyViewHolder)viewHolder).llitem, dX, dY, actionState, isCurrentlyActive);

        }
      //重绘item，在item上面
        @Override
        public void onChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {

            getDefaultUIUtil().onDraw(c,recyclerView,((MyViewHolder)viewHolder).llitem, dX, dY, actionState, isCurrentlyActive);

        }
        //清理视图，回到默认状态
        @Override
        public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
            getDefaultUIUtil().clearView(((MyViewHolder)viewHolder).llitem);
        }
    };

adapter

 class  RecyclerAdapter extends RecyclerView.Adapter
    {

        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view  = LayoutInflater.from(MainActivity.this).inflate(R.layout.item_recycler,parent,false);

            return new MyViewHolder(view);
        }

      //判断滑动的方向
        void onItemMove(int from,int to)
        {
            if(fromto)
            {
                for(int i=0;i

设置RecyclerView

  mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());


        adapter = new RecyclerAdapter();
        ItemTouchHelper helper = new ItemTouchHelper(callback);
        //RecyclerView与ItemTouchHelper连接起来
        helper.attachToRecyclerView(mRecyclerView);


        mRecyclerView.setAdapter(adapter);
        adapter.notifyDataSetChanged();