ItemToucherHelper 不会在带有垂直 LinearLayoutManager 的 recyclerView 中滑动

问题描述

我正在尝试将 itemtouchhelper 附加到我的 recyclerView 以实现滑动读取功能，我有 itemtouchhelper.Callback 的代码：

public class MessageCommentSwipeCallback extends itemtouchhelper.Callback {
    private static final String TAG="MessageSwipeCallback";
    private final MessageCommentAdapter adapter;

    public MessageCommentSwipeCallback(MessageCommentAdapter adapter) {
        this.adapter = adapter;
        Log.i(TAG,"MessageCommentSwipeCallback: ");
    }

    @Override
    public int getMovementFlags(@NonNull RecyclerView recyclerView,@NonNull RecyclerView.ViewHolder viewHolder) {
        Log.i(TAG,"getMovementFlags: ");
        int dragFlags = itemtouchhelper.UP | itemtouchhelper.DOWN;        //允许上下的拖动
        int swipeFlags = itemtouchhelper.LEFT;   //只允许从右向左侧滑
        return makeFlag(dragFlags,swipeFlags);
    }

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

    @Override
    public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder,int direction) {
        Log.i(TAG,"onSwiped: ");
        adapter.onMessageRead(viewHolder.getAbsoluteAdapterPosition());
    }

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

    @Override
    public boolean isItemViewSwipeEnabled() {
        Log.i(TAG,"isItemViewSwipeEnabled: ");
        return true;
    }
}

我在这段代码中将它附加到 recyclerView：

public class MessageCommentFragment extends Fragment {

    private static final String TAG = "MessageCommentFragment";
    private FragmentMessageCommentBinding binding;
    private MessageCommentviewmodel messageCommentviewmodel;
    private MessageCommentAdapter adapter;

    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
        binding = FragmentMessageCommentBinding.inflate(inflater);
        //here omit unimportant code
        binding.recyclerViewMessageComment.setLayoutManager(new linearlayoutmanager(getContext()));
        return binding.getRoot();
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        //为recyclerView添加左滑监听
        MessageCommentSwipeCallback callback=new MessageCommentSwipeCallback(adapter);
        itemtouchhelper itemtouchhelper=new itemtouchhelper(callback);
        itemtouchhelper.attachToRecyclerView(binding.recyclerViewMessageComment);
        //here omit unimportant code
    }
}

但是，即使我的 logcat 打印了有关“getMovementFlags”和“isItemViewSwipeEnabled”方法的信息，也没有滑动动画，也没有 logcat 信息对于方法“onSwiped”。这是 logcat 信息：

2021-04-01 11:14:55.922 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: isItemViewSwipeEnabled: 
2021-04-01 11:14:55.939 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: isItemViewSwipeEnabled: 
2021-04-01 11:14:55.939 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: getMovementFlags: 
2021-04-01 11:14:55.955 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: isItemViewSwipeEnabled: 
2021-04-01 11:14:55.955 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: getMovementFlags: 
2021-04-01 11:14:55.971 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: isItemViewSwipeEnabled: 
2021-04-01 11:14:55.971 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: getMovementFlags: 
2021-04-01 11:14:55.988 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: isItemViewSwipeEnabled: 
2021-04-01 11:14:55.988 15994-15994/com.cztcode.dailymoments I/MessageSwipeCallback: getMovementFlags: 

我无法弄清楚发生了什么。请帮帮我。

解决方法

您应该在 getMovementFlags 中使用 makeMovementFlags 而不是 makeFlags。

您也可以使用我制作的库来执行此操作。

这是link