Question

首先，我整天都在努力，但无法完成任何事情。我有RecyclerView一个使用RecyclerView＆＃39; s SortedList的适配器。我尝试使用回调类实现TouchHelper：

public class TimerListTouchHelperCallback extends ItemTouchHelper.SimpleCallback {

    private OnItemChangeListener onItemChangeListener;

    public TimerListTouchHelperCallback(OnItemChangeListener listener, int dragDirs, int swipeDirs) {
        super(dragDirs, swipeDirs);

        this.onItemChangeListener = listener;

    }

    @Override
    public int getSwipeDirs(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        TimerHolder holder = (TimerHolder) viewHolder;

        int holderState = holder.getState();

        if (holderState == TimerHolder.TIMER_PENDING_DELETE) return 0;
        else return super.getSwipeDirs(recyclerView, viewHolder);
    }

    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        return false;
    }




    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
        TimerHolder holder = (TimerHolder) viewHolder;

        int position = holder.getAdapterPosition();
        // ViewHolder's state is changed that should handle the layout change.
        holder.setState(TimerHolder.TIMER_PENDING_DELETE); 

        if (onItemChangeListener != null) onItemChangeListener.onItemSwiped(position);
    }


    protected interface OnItemChangeListener{
        void onItemSwiped(int position);
    }
}

这是TouchHelper的初始化

timerAdapter = new TimerAdapter(this, timerList);
    timerListView.setAdapter(timerAdapter);

TimerListTouchHelperCallback touchHelperCallback = new TimerListTouchHelperCallback(
        timerAdapter,
        ItemTouchHelper.LEFT,
        ItemTouchHelper.LEFT);

ItemTouchHelper swipeToDismissTouchHelper = new ItemTouchHelper(touchHelperCallback);

swipeToDismissTouchHelper.attachToRecyclerView(timerListView);

我的适配器实现了接口OnItemChangeListener

@Override
public void onItemSwiped(int position) {
    notifyItemChanged(position);
    removalPendingTimers.add(timerList.get(position));
}

我的ViewHolder读取状态，当状态为TimerHolder.TIMER_PENDING_DELETE时，它会隐藏视图的其余部分并显示带有撤消按钮的界面。但是直到我滚动视图并再次向后滚动它才会发生这种情况。有什么建议我缺少什么吗？

链接

Adapter class ViewHolder class

Answer 1

终于让它运行了。由于notifyItemRemoved没有削减它（它应该有），我使用notifyItemInserted后跟{{1}}。

稍微停滞一下但是有效。

Answer 2

我已经创建了一个简单的Android应用示例来更好地理解这个问题。

当用户向左或向右滑动项目以显示撤消视图时，它会使用 notifyItemChanged（position）; 。当撤消时间到期时，它会调用 notifyItemRemoved（position）将其从列表中删除。例如，请参阅GIF，不要留下任何空行。

https://github.com/DawidvanGraan/ExampleRecycleViewSwipeDismiss

notifyItemChanged没有刷新视图

2 个答案: