android - 不同 ViewType 之间的 NotifyItemMoved 不起作用

Question

我已经解决这个问题很多天了，看不到尽头，所以任何帮助都将不胜感激!这是问题所在:

我有一个房间数据库和一个回收站 View ，我在其中显示了该数据库的一部分。通常一切正常。但是，如果我尝试拖动(从而切换顺序)两个具有不同 View 类型的项目，适配器会将项目放回原来的位置。

之前的堆栈溢出问题很好地展示了问题:Android RecyclerView: drag and drop over multiple ViewType

代码:(在 fragment java中)

        // Configuring RecycleView
        RecyclerView recyclerView = root.findViewById(R.id.recyclerview_viewpager_schedule);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        recyclerView.setHasFixedSize(true);

        // configuring Adapter
        daysAdapter = new DaysAdapter();
        
        prevfrom = -1;
        flagish = -1;


        //daysAdapter.setHasStableIds(true);
        recyclerView.setAdapter(daysAdapter);

        daysViewModel.getNotesInDay(args.getInt(ARG_OBJECT)).observe(getViewLifecycleOwner(), new Observer<List<DayActivity>>() {
            @Override
            public void onChanged(List<DayActivity> dayActivities) {
                //I use a flag in order for the list not to update onMove because that makes a weird looking effect. It updates later on and it works just fine!
                if (flagish != 5) daysAdapter.submitList(dayActivities);
                flagish = 1;

            }
        });

        ItemTouchHelper mIth = new ItemTouchHelper(
                new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN, 0) {
                    @RequiresApi(api = Build.VERSION_CODES.N)
                    @Override
                    public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
                        final int fromPos = viewHolder.getAdapterPosition();
                        final int toPos = target.getAdapterPosition();

                        Log.d("onMove", "From:" + fromPos);
                        Log.d("onMove", "to:" + toPos);

                        Log.d("STOP_HERE_please_1", fromPos + "   " + toPos);
                        Bundle arguments = getArguments();
                        Log.d("STOP_HERE_3", String.valueOf(arguments.getInt(ARG_OBJECT)));

                        if (fromPos==toPos) return false;

                        //prevFrom is the previous fromPos in case the item hansn't been dropped yet
                        if (prevfrom == -1) prevfrom = fromPos;
                        if (prevfrom == toPos) return false;
                        getView().clearFocus();

                        // Change position

                       DayActivity lItem;
                        newList = new ArrayList<>();

                        int lIncrement = (fromPos<toPos) ? -1 : +1; //  true if scroll down
                        int lMax = Integer.max(prevfrom, toPos);
                        int lMin = Integer.min(prevfrom, toPos);

                        List<DayActivity>oldList =daysAdapter.getOrdersBetween(lMin, lMax);
                        //This function (getOrdersBetween) gets the DayActivities whose positions are between those two values
                        for (int i=lMin; i<= lMax; i++) {
                            lItem = oldList.get(i);
                            if (i == fromPos) {
                                lItem.setOrder_Day(toPos);
                            } else
                                lItem.setOrder_Day(lItem.getOrder_Day() + lIncrement);
                            //The program uses the order to order the items in the recycler view
                            newList.add(lItem);
                        }

                        daysAdapter.notifyItemMoved(fromPos, toPos);

                        return true;

                    }

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

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

                    @Override
                    public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int direction) {
                    }

                    @Override
                    public void onSelectedChanged(@Nullable RecyclerView.ViewHolder viewHolder, int actionState) {
                        super.onSelectedChanged(viewHolder, actionState);
                        if (actionState == ACTION_STATE_DRAG)
                            viewHolder.itemView.setAlpha(0.5f);
                    }

                    @Override
                    public void clearView(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
                        super.clearView(recyclerView, viewHolder);
                        viewHolder.itemView.setAlpha(1.0f);
                        flagish = 5;
                        if(newList != null) daysViewModel.updateList(newList);
                        prevfrom = -1;
                    }

我相信问题是在 adapter.notifyitemmoved 中路由的，但我一直无法解决它!有些人在其他帖子中建议我使用 sethasStableIds()，但是这个函数只会导致 notifyItemMoved 产生类似的效果，即使这两个项目具有相似的 View 类型。

我认为没有必要用适配器中的代码重载这篇文章，但如果有人需要，请告诉我。谢谢!!!

Answer 1

NotifyItemMoved 应该适用于不同的 ViewType。

我假设您正在使用 AsyncDiffer？检查您是否覆盖适配器 getItemViewType(position) 功能正确，也许您正在从尚未同步的 AsyncDiffers 当前列表中获取位置？