android-如何捕捉与RecycerView一起使用的ItemTouchHelper的Drop动作

Question

private void initializeLayout() {
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutFrozen(true);
    recyclerView.setNestedScrollingEnabled(false);

    // set layout manager
    GridLayoutManager layoutManager = new GridLayoutManager(getContext(), BOARD_SIZE,
        LinearLayoutManager.VERTICAL, true);
    recyclerView.setLayoutManager(layoutManager);

    // Extend the Callback class
    ItemTouchHelper.Callback itemTouchCallback = new ItemTouchHelper.Callback() {

    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        Log.w(TAG, "onMove");
        return false;
    }

    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
        // Application does not include swipe feature.
    }

    @Override
    public void onMoved(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder,
                        int fromPos, RecyclerView.ViewHolder target, int toPos, int x, int y) {
        Log.d(TAG, "onMoved");
        // this is calling every time, but I need only when user dropped item, not after every onMove function.
    }

    @Override
    public boolean isItemViewSwipeEnabled() {
        return false;
    }

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

    @Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.START | ItemTouchHelper.END;
        int swipeFlags = 0;
        return makeMovementFlags(dragFlags, swipeFlags);
    }
    };

    ItemTouchHelper touchHelper = new ItemTouchHelper(itemTouchCallback);
    touchHelper.attachToRecyclerView(recyclerView);
}

那么，为什么ItemTouchHelper的onMoved函数在我还在RecycerView上拖动item时还能工作呢？我怎样才能做到这一点？

Answer 1

必须在适配器中实现OnMove侦听器：

collections.swap（youCoolList,fromPosition,toPosition）；notifyItemMoved（fromPosition,toPosition）；

就像这个人在做https://medium.com/@ipaulpro/drag-and-swipe-with-recyclerview-b9456d2b1aaf#.blviq6jxp