我的应用程序不断收到错误消息，提示 I/Choreographer:跳过 252 帧!应用程序可能在其主线程上做了太多工作。 我认为这会导致我的 UI 出现一些延迟，这是我不希望的。我认为这是因为当我执行 Firebase 查询时，当我执行 onDataChange() 时，它似乎总是在主 UI 线程中执行。我有大约 5 个类似于下面的 Firebase 查询。因此，我尝试将我的代码从 onDataChange() 方法移动到 AsyncTask 并在 onPostExecute() 方法上更新 UI 线程异步任务。但是，当我尝试这样做时，onPostExecute() 方法永远不会完成。这是我的尝试:

public void getPublicPosts(final View progressOverlay, final View fragmentView, final Context context) {
    //Need to do order by / equal to.
    Firebase postsRef = firebaseRef.child("Posts");
    Query query = postsRef.orderByChild("privacy").equalTo("Public");
    query.keepSynced(true);
    query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (final DataSnapshot postSnapShot : dataSnapshot.getChildren()) {
                AsyncTask task = new AsyncTask<URL, Integer, Long>() {
                    @Override
                    protected Long doInBackground(URL... params) {
                        Post post = postSnapShot.getValue(Post.class);
                        List<Post> publicPosts = application.getPublicAdapter().getPosts();
                        if (post.getPrivacy().equals("Public") && application.getPublicAdapter().containsId(publicPosts, post.getId()) == null) {
                            application.getPublicAdapter().getPosts().add(0, post);
                        }
                        return null;
                    }
                    @Override
                    protected void onProgressUpdate(Integer... progress) {
                    }

                    @Override
                    protected void onPostExecute(Long result) {
                        System.out.println("Finished executing public");
                        populateNewsFeedList(fragmentView, application.getPublicAdapter(), TabEnum.Public, context);
                        if (progressOverlay.getVisibility() == View.VISIBLE) {
                            System.out.println("getPublicPosts: DONE");
                            AndroidUtils.animateView(progressOverlay, View.GONE, 0, 200);
                            fragmentView.findViewById(R.id.rv_public_feed).setVisibility(View.VISIBLE);
                        }
                    }
                };
                `task.execute();`
            }
        }

        @Override
        public void onCancelled(FirebaseError firebaseError) {
        }
    });
}

任何对此的帮助都会有所帮助。如果有人可以帮助我，那就太好了。谢谢!

编辑:添加函数来创建AsyncTask

public AsyncTask asyncTaskWrapper(final DataSnapshot dataSnapshot, final View progressOverlay, final View fragmentView, final Context context) {
        AsyncTask task = new AsyncTask<URL, Integer, Long>() {
            @Override
            protected Long doInBackground(URL... params) {
                for (final DataSnapshot postSnapShot : dataSnapshot.getChildren()) {
                    Post post = postSnapShot.getValue(Post.class);
                    List<Post> publicPosts = application.getPublicAdapter().getPosts();
                    if (post.getPrivacy() == PrivacyEnum.Public && application.getPublicAdapter().containsId(publicPosts, post.getId()) == null) {
                        application.getPublicAdapter().getPosts().add(0, post);
                    }
                }
                return null;
            }
            @Override
            protected void onProgressUpdate(Integer... progress) {
            }

            @Override
            protected void onPostExecute(Long result) {
                System.out.println("Finished executing public");
                TabsUtil.populateNewsFeedList(fragmentView, application.getPublicAdapter(), TabEnum.Public, context);
                if (progressOverlay.getVisibility() == View.VISIBLE) {
                    System.out.println("getPublicPosts: GONE");
                    AndroidUtils.animateView(progressOverlay, View.GONE, 0, 200);
                    fragmentView.findViewById(R.id.rv_public_feed).setVisibility(View.VISIBLE);
                }
            }
        };
        return task;
    }

公共(public)帖子功能:

public void getPublicPosts(final View progressOverlay, final View fragmentView, final Context context) {
    //Need to do order by / equal to.
    Firebase postsRef = firebaseRef.child("Posts");
    Query query = postsRef.orderByChild("privacy").equalTo(PrivacyEnum.Public.toString());
    query.keepSynced(true);
    query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            asyncTaskWrapper(dataSnapshot, progressOverlay, fragmentView, context);
        }

        @Override
        public void onCancelled(FirebaseError firebaseError) {
            TabsUtil.populateNewsFeedList(fragmentView, application.getPublicAdapter(), TabEnum.Public, context);
        }
    });
}

最佳答案

您的主线程可能很慢，因为您正在运行一个包含许多对象的循环。但是，不知道您到底在执行什么，这只是一个猜测。

但我对您的 AsyncTask 有疑问，我认为它永远无法与您发布的代码一起使用。

AsyncTask 需要一个 URL 数组。你没有通过任何。如果不需要 URL 作为输入，则只需使用:

AsyncTask task = new AsyncTask<Void, Boolean, Boolean>() 

你试试如何排除故障:

    AsyncTask task = new AsyncTask<URL, Boolean, Boolean>() {
        @Override
        protected Boolean doInBackground(URL... params) {
            for (final DataSnapshot postSnapShot : dataSnapshot.getChildren()) {
                Post post = postSnapShot.getValue(Post.class);
                List<Post> publicPosts = application.getPublicAdapter().getPosts();
                if (post.getPrivacy() == PrivacyEnum.Public && application.getPublicAdapter().containsId(publicPosts, post.getId()) == null) {
                    application.getPublicAdapter().getPosts().add(0, post);
                }
            }
            return true;
        }

        @Override
        protected void onPostExecute(Boolean result) {
            if(result){
                System.out.println("Finished executing public");
                TabsUtil.populateNewsFeedList(fragmentView, application.getPublicAdapter(), TabEnum.Public, context);
                if (progressOverlay.getVisibility() == View.VISIBLE) {
                    System.out.println("getPublicPosts: GONE");
                    AndroidUtils.animateView(progressOverlay, View.GONE, 0, 200);
                    fragmentView.findViewById(R.id.rv_public_feed).setVisibility(View.VISIBLE);
                }
            }
        }
    };

然后通过触发来执行任务:

URL[] urls = new URL[2];
urls[0] = new URL(...);
urls[1] = new URL(...);
task.execute(urls);

如果代码失败，请使用 IDE 中的调试功能并返回确切位置。

关于java - 由于异步 Firebase 调用，主线程做了太多工作？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37532188/