Android在RecyclerView中实现拖拽和滑动删除的效果

参考
1、http://stackoverflow.com/questions/27293960/swipe-to-dismiss-for-recyclerview/30601554#30601554
2、https://developer.android.com/reference/android/support/v7/widget/helper/ItemTouchHelper.SimpleCallback.html
3、https://medium.com/@ipaulpro/drag-and-swipe-with-recyclerview-b9456d2b1aaf

效果如下：

1、更新Android Support Library

compile 'com.android.support:recyclerview-v7:22.2.+'

2、new一个SimpleCallback出来

ItemTouchHelper.SimpleCallback callback = new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN,
                ItemTouchHelper.LEFT) {
            @Override
            public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder source, RecyclerView.ViewHolder target) {
                final int fromPos = source.getAdapterPosition();
                final int toPos = target.getAdapterPosition();
                mAdapter.mOnMove(fromPos, toPos);
                return true;
            }

            @Override
            public void onSwiped(RecyclerView.ViewHolder viewHolder, int i) {
                mAdapter.mOnSwiped(viewHolder);
            }
        };

他有两个参数，第一个为drag操作的方向，第二个为swipe操作的方向。
在onMove方法中具体写移动拖拽item的操作，onSwiped中写滑动的操作。

// drag的具体操作
    public void mOnMove(int fromPos,int toPos) {
        String prev = mList.remove(fromPos);
        mList.add(toPos > fromPos ? toPos - 1 : toPos, prev);
        notifyItemMoved(fromPos, toPos);
    }

// swipe的具体操作
    public void mOnSwiped(RecyclerView.ViewHolder viewHolder) {
        mList.remove(viewHolder.getAdapterPosition());
        notifyItemRemoved(viewHolder.getAdapterPosition());
    }

3、new一个ItemTouchHelper

ItemTouchHelper mItemTouchHelper = new ItemTouchHelper(callback);

4、把ItemTouchHelper和RecyclerView关联

mItemTouchHelper.attachToRecyclerView(mRecyclerView);

源码如下
https://github.com/mmga/ItemTouchHelperDemo-SimpleCallback