Recycleview notifyDataSetChanged（）erro

Question

我试图查看其他答案，但他们没有解决我的问题。每次我想在recyview中加载项目并且无休止地滚动时，我的recyclelerview会出现错误。有时它会将项目加载到recyclerview，有时它会将回收视图留空，并在logcat上给出一条消息，如下所示。

IllegalStateException: Cannot call this method while RecyclerView is computing a layout or scrolling

我的申请类是

itemAdapter.setOnLoadMoreListener(new Schoolarship_Adapter.OnLoadMoreListener() {
        @Override
        public void onLoadMore() {
            listItem.add(null);
            itemAdapter.notifyItemInserted(listItem.size() - 1);

            final Handler handler = new Handler();

            final Runnable r = new Runnable() {
                @Override
                public void run() {
                    listItem.remove(listItem.size() - 1);
                    itemAdapter.notifyItemRemoved(listItem.size());

                    ++pagenumber;
                    new RetrieveItems().execute();
                    System.out.println("working now i guess");

                    itemAdapter.notifyDataSetChanged();
                    itemAdapter.setLoaded();

                }
            };

            handler.post(r);
        }
    });

我的适配器看起来像

Schoolarship_Adapter(Context cont, List<Schoolarship> items, @NonNull RecyclerView rv){
    context = cont;
    listItems = items;

    if((rv.getLayoutManager() instanceof LinearLayoutManager)) {
        final LinearLayoutManager gm = (LinearLayoutManager) rv.getLayoutManager();
        rv.setOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy){
                super.onScrolled(recyclerView, dx, dy);
                totalItemCount = gm.getItemCount();
                lastVisibleItem = gm.findLastVisibleItemPosition();
                if(!loading &&totalItemCount <= (lastVisibleItem + visibleThreshold)){
                    if(onLoadMoreListener!=null){
                        onLoadMoreListener.onLoadMore();
                    }
                    loading = true;
                }
            }
        });
    }
}

请问，为什么每次运行此应用程序时仍然会出现错误？

Answer 1

原因是，你的onLoadMore（） 它会在添加/加载新项目时计算recyclerView的高度，所以当你给notifyDataSetChanged它肯定会抛出异常。 也许这会起作用

protected void postAndNotifyAdapter(final Handler handler, final RecyclerView recyclerView, final RecyclerView.Adapter adapter) {
        handler.post(new Runnable() {
            @Override
            public void run() {
                if (!recyclerView.isComputingLayout()) {
                    adapter.notifyDataSetChanged();
                } else {
                    postAndNotifyAdapter(handler, recyclerView, adapter);
                }
            }
        });
    }