android - 无法从 RecyclerView.OnScrollListener 调用 notifyItemInserted()

Question

最近我将我的 recyclerview-v7:23 升级到 recyclerview-v7:24.2.0。我的应用程序有一个无穷无尽的滚动列表。当我将加载 View 添加到 RecyclerView 时，错误消息指向行 notifyItemInserted (空对象表示加载，id 0 为空，-1 为页面末尾)和它之前工作正常(recyclerview-v7:23)，但突然我遇到了这样的错误，不知何故我的加载显示了两次，然后当它删除一个时，顶部仍然可见一个加载。

    W/RecyclerView: Cannot call this method in a scroll callback. Scroll callbacks might be run during a measure & layout pass where you cannot change the RecyclerView data. Any method call that might change the structure of the RecyclerView or the adapter contents should be postponed to the next frame.java.lang.IllegalStateException:  
 at android.support.v7.widget.RecyclerView.assertNotInLayoutOrScroll(RecyclerView.java:2403)
     at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onItemRangeInserted(RecyclerView.java:4631)
     at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyItemRangeInserted(RecyclerView.java:10469)
     at android.support.v7.widget.RecyclerView$Adapter.notifyItemInserted(RecyclerView.java:6211)
     at com.sketchproject.infogue.fragments.MessageFragment.loadMessages(MessageFragment.java:109)
     at com.sketchproject.infogue.fragments.MessageFragment.access$100(MessageFragment.java:42)
     at com.sketchproject.infogue.fragments.MessageFragment$1.onLoadMore(MessageFragment.java:87)
     at com.sketchproject.infogue.modules.EndlessRecyclerViewScrollListener.onScrolled(EndlessRecyclerViewScrollListener.java:74)

当我删除错误部分(添加加载)时它再次正常工作，我不知道为什么，较新版本的 recyclerview 阻止将数据添加到适配器中太快或者在“测量 & recyclerview 的布局”完成，这是我的代码

private void loadArticles(final int page) {
        if (!isEndOfPage && apiArticleUrl != null) {
            if (swipeRefreshLayout == null || !swipeRefreshLayout.isRefreshing()) {
                allArticles.add(null);
                articleAdapter.notifyItemInserted(allArticles.size() - 1); // error here
            }

            JsonObjectRequest articleRequest = new JsonObjectRequest(Request.Method.GET, apiArticleUrl, null,
                    new Response.Listener<JSONObject>() {
                        @Override
                        public void onResponse(JSONObject response) {

                            try {
                                String status = response.getString("status");
                                JSONObject articles = response.getJSONObject("articles");

                                String nextUrl = articles.getString("next_page_url");
                                int currentPage = articles.getInt("current_page");
                                int lastPage = articles.getInt("last_page");
                                JSONArray data = articles.optJSONArray("data");

                                apiArticleUrl = nextUrl;

                                if (status.equals(APIBuilder.REQUEST_SUCCESS)) {
                                    if (swipeRefreshLayout == null || !swipeRefreshLayout.isRefreshing()) {
                                        allArticles.remove(allArticles.size() - 1);
                                        articleAdapter.notifyItemRemoved(allArticles.size());
                                    } else {
                                        swipeRefreshLayout.setRefreshing(false);
                                        int total = allArticles.size();
                                        for (int i = 0; i < total; i++) {
                                            allArticles.remove(0);
                                        }
                                        articleAdapter.notifyItemRangeRemoved(0, total);
                                    }

                                    List<Article> moreArticles = new ArrayList<>();

                                    if (data != null) {
                                        for (int i = 0; i < data.length(); i++) {
                                            JSONObject articleData = data.getJSONObject(i);
                                            Article article = new Article();
                                            article.setId(articleData.getInt(Article.ID));
                                            article.setSlug(articleData.getString(Article.SLUG));
                                            article.setTitle(articleData.getString(Article.TITLE));
                                            article.setFeatured(articleData.getString(Article.FEATURED_REF));
                                            article.setCategoryId(articleData.getInt(Article.CATEGORY_ID));
                                            article.setCategory(articleData.getString(Article.CATEGORY));
                                            article.setSubcategoryId(articleData.getInt(Article.SUBCATEGORY_ID));
                                            article.setSubcategory(articleData.getString(Article.SUBCATEGORY));
                                            article.setContent(articleData.getString(Article.CONTENT));
                                            article.setContentUpdate(articleData.getString(Article.CONTENT_UPDATE));
                                            article.setPublishedAt(articleData.getString(Article.PUBLISHED_AT));
                                            article.setView(articleData.getInt(Article.VIEW));
                                            article.setRating(articleData.getInt(Article.RATING_TOTAL));
                                            article.setStatus(articleData.getString(Article.STATUS));
                                            moreArticles.add(article);
                                        }
                                    }

                                    int curSize = articleAdapter.getItemCount();
                                    allArticles.addAll(moreArticles);

                                    if (allArticles.size() <= 0) {
                                        Log.i("INFOGUE/Article", "Empty on page " + page);
                                        isEndOfPage = true;
                                        Article emptyArticle = new Article(0, null, "Empty page");
                                        allArticles.add(emptyArticle);
                                    } else if (currentPage >= lastPage) {
                                        Log.i("INFOGUE/Article", "End on page " + page);
                                        isEndOfPage = true;
                                        Article endArticle = new Article(-1, null, "End of page");
                                        allArticles.add(endArticle);
                                    }

                                    articleAdapter.notifyItemRangeInserted(curSize, allArticles.size() - 1);
                                } else {
                                    Log.i("INFOGUE/Article", "Error on page " + page);
                                    Helper.toastColor(getContext(), R.string.error_unknown, R.color.color_warning_transparent);

                                    isEndOfPage = true;
                                    Article failureArticle = new Article();
                                    failureArticle.setId(-2);
                                    failureArticle.setTitle(getString(R.string.error_unknown));
                                    allArticles.add(failureArticle);
                                }
                            } catch (JSONException e) {
                                e.printStackTrace();
                            }
                        }
                    },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            error.printStackTrace();

                            if (swipeRefreshLayout != null && swipeRefreshLayout.isRefreshing()) {
                                swipeRefreshLayout.setRefreshing(false);
                            }

                            // remove last loading
                            allArticles.remove(allArticles.size() - 1);
                            articleAdapter.notifyItemRemoved(allArticles.size());

                            String errorMessage = getString(R.string.error_unknown);
                            NetworkResponse networkResponse = error.networkResponse;
                            if (networkResponse == null) {
                                if (error.getClass().equals(TimeoutError.class)) {
                                    errorMessage = getString(R.string.error_timeout);
                                } else if (error.getClass().equals(NoConnectionError.class)) {
                                    errorMessage = getString(R.string.error_no_connection);
                                }
                            } else {
                                if (networkResponse.statusCode == 404) {
                                    errorMessage = getString(R.string.error_not_found);
                                } else if (networkResponse.statusCode == 500) {
                                    errorMessage = getString(R.string.error_server);
                                } else if (networkResponse.statusCode == 503) {
                                    errorMessage = getString(R.string.error_maintenance);
                                }
                            }
                            Helper.toastColor(getContext(), errorMessage, R.color.color_danger_transparent);

                            // add error view holder
                            isEndOfPage = true;
                            Article errorArticle = new Article();
                            errorArticle.setId(-2);
                            errorArticle.setTitle(errorMessage);
                            allArticles.add(errorArticle);
                        }
                    }
            );

            articleRequest.setTag("articles");
            articleRequest.setRetryPolicy(new DefaultRetryPolicy(
                    APIBuilder.TIMEOUT_SHORT,
                    DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                    DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
            VolleySingleton.getInstance(getContext()).addToRequestQueue(articleRequest);
        }
    }

该代码是从 onCreate 方法调用的

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.fragment_article_list, container, false);

            // Set the adapter
            if (view instanceof RecyclerView) {
                Context context = view.getContext();
                recyclerView = (RecyclerView) view;

                // determine column of list
                LinearLayoutManager linearLayoutManager;
                if (mColumnCount <= 1) {
                    linearLayoutManager = new LinearLayoutManager(context);
                } else {
                    linearLayoutManager = new GridLayoutManager(context, mColumnCount);
            }

        // if article list authored by logged user then prefer editable view holder
        if (mMyArticle) {
            articleAdapter = new ArticleRecyclerViewAdapter(allArticles, mArticleListListener, mArticleEditableListener);
        } else {
            articleAdapter = new ArticleRecyclerViewAdapter(allArticles, mArticleListListener, hasHeader);
        }

        // set the adapter and attach custom scroll listener that triggered onLoadMore() and onReachTop()
        recyclerView.setAdapter(articleAdapter);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener(linearLayoutManager) {
            @Override
            public void onLoadMore(final int page, int totalItemsCount) {
                if (!isFirstCall) {
                    loadArticles(page);
                }
            }

            @Override
            public void onReachTop(boolean isFirst) {
                // activate swipe function when list reach top only, find out where do fragment attached
                if (getActivity() instanceof ArticleActivity) {
                    ((ArticleActivity) getActivity()).setSwipeEnable(isFirst);
                } else if (getActivity() instanceof ApplicationActivity) {
                    ((ApplicationActivity) getActivity()).setSwipeEnable(isFirst);
                }
            }
        });

        if (isFirstCall) {
            isFirstCall = false;
            loadArticles(0);
        }
    }
    return view;
} 

我的问题是:

1. 问题是否来自新版本的 RecyclerView？
2. 在滚动监听器中实现 notifyItemInserted 有错吗？它以前工作过。
3. 我该如何解决这个问题？

更新

when I logged the code inside first call and scroll,
09-12 03:49:10.078 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:26.421 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers first call
09-12 03:49:26.421 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:26.617 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers second call (scroll)
09-12 03:49:26.618 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers URL http://192.168.43.141:8000/api/contributor/support/followers?contributor_id=1
09-12 03:49:27.365 7046-7046/com.sketchproject.infogue I/Infogue/Contributor: Followers second call (scroll)

它们在第一次加载时被调用两次，在第一次调用并添加加载 View 后，滚动被触发并再次调用。

Answer 1

您也可以使用 View 发布。

   recyclerView.post(new Runnable() {
        public void run() {
            articleAdapter.notifyItemInserted(allArticles.size() - 1);
        }
    });