异步任务中未调用onPostExecute(处理程序运行时异常)

我有一个 AsyncTask 它获取一些数据,然后用这些新数据更新UI。它已经工作了好几个月了,但是我最近添加了一个功能,当有新数据时,它会显示一个通知。现在,当我的应用程序通过通知启动时,有时会出现此异常并 onPostExecute 不被调用。

应用程序启动时会发生以下情况:

1)展开UI并查找视图

2)取消警报(通过 AlarmManager )它检查新数据并重置警报。(这样,如果用户禁用警报,则在下次重新启动之前取消警报。)

3)启动 异步任务 . 如果应用程序是从通知中启动的,请传入一点数据,然后取消通知。

我不明白是什么导致了这个异常。似乎例外是 异步任务 代码,所以我不确定如何修复它。

谢谢!

以下是例外情况:

I/My App(  501): doInBackground exiting
W/MessageQueue(  501): Handler{442ba140} sending message to a Handler on a dead thread
W/MessageQueue(  501): java.lang.RuntimeException: Handler{442ba140} sending message to a Handler on a dead thread
W/MessageQueue(  501):  at android.os.MessageQueue.enqueueMessage(MessageQueue.java:179)
W/MessageQueue(  501):  at android.os.Handler.sendMessageAtTime(Handler.java:457)
W/MessageQueue(  501):  at android.os.Handler.sendMessageDelayed(Handler.java:430)
W/MessageQueue(  501):  at android.os.Handler.sendMessage(Handler.java:367)
W/MessageQueue(  501):  at android.os.Message.sendToTarget(Message.java:348)
W/MessageQueue(  501):  at android.os.AsyncTask$3.done(AsyncTask.java:214)
W/MessageQueue(  501):  at java.util.concurrent.FutureTask$Sync.innerSet(FutureTask.java:252)
W/MessageQueue(  501):  at java.util.concurrent.FutureTask.set(FutureTask.java:112)
W/MessageQueue(  501):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:310)
W/MessageQueue(  501):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
W/MessageQueue(  501):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
W/MessageQueue(  501):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
W/MessageQueue(  501):  at java.lang.Thread.run(Thread.java:1096)

编辑:这是我的 onCreate 方法(由通知打开的活动)。有一些 onClickListeners 我忘了节省空间。我认为它们不应该有任何效果,因为它们所附的按钮没有被按下。

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); // Call the parent

    setContentView(R.layout.main); // Create the UI from the XML file

    // Find the UI elements
    controls = (SlidingDrawer) findViewById(R.id.drawer); // Contains the
    // buttons
    // comic = (ImageView) findViewById(R.id.comic); // Displays the comic
    subtitle = (TextView) findViewById(R.id.subtitleTxt); // Textbox for the
    // subtitle
    prevBtn = (Button) findViewById(R.id.prevBtn); // The previous button
    nextBtn = (Button) findViewById(R.id.nextBtn); // The next button
    randomBtn = (Button) findViewById(R.id.randomBtn); // The random button
    fetchBtn = (Button) findViewById(R.id.comicFetchBtn); // The go to specific id button
    mostRecentBtn = (Button) findViewById(R.id.mostRecentBtn); // The button to go to the most recent comic
    comicNumberEdtTxt = (EditText) findViewById(R.id.comicNumberEdtTxt); // The text box to Zooming image view setup
    zoomControl = new DynamicZoomControl();

    zoomListener = new LongPressZoomListener(this);
    zoomListener.setZoomControl(zoomControl);

    zoomComic = (ImageZoomView) findViewById(R.id.zoomComic);
    zoomComic.setZoomState(zoomControl.getZoomState());
    zoomComic.setImage(BitmapFactory.decodeResource(getResources(), R.drawable.defaultlogo));
    zoomComic.setOnTouchListener(zoomListener);

    zoomControl.setAspectQuotient(zoomComic.getAspectQuotient());

    resetZoomState();

    // enter the new id
    imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE); // Used to hide the soft keyboard

    Log.i(LOG_TAG, "beginning loading of first comic");
    int notificationComicNumber = getIntent().getIntExtra("comic", -1);
    Log.i(LOG_TAG, "comic number from intent: " + notificationComicNumber);
    if (notificationComicNumber == -1) {
        fetch = new MyFetcher(this, zoomComic, subtitle, controls, comicNumberEdtTxt, imm, zoomControl);
        fetch.execute(MyFetcher.LAST_DISPLAYED_COMIC);
    } else {
        fetch = new MyFetcher(this, zoomComic, subtitle, controls, comicNumberEdtTxt, imm, zoomControl);
        fetch.execute(notificationComicNumber);
        ((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE)).cancelAll();
    }
    Log.i(LOG_TAG, "ending loading of new comic");

    Log.i(LOG_TAG, "first run checks beginning");
    // Get SharedPreferences
    prefs = getSharedPreferences("prefs", Context.MODE_PRIVATE);

    // Check if this is the first run of the app for this version
    if (prefs.getBoolean("firstRun-" + MAJOR_VERSION_NUMBER, true)) {
        prefs.edit().putBoolean("firstRun-" + MAJOR_VERSION_NUMBER, false).commit();
        firstRunVersionDialog();
    }

    // Check if this is the first run of the app
    if (prefs.getBoolean("firstRun", true)) {
        prefs.edit().putBoolean("firstRun", false).commit();
        firstRunDialog();
    }
    Log.i(LOG_TAG, "First run checks done");

            // OnClickListener s for the buttons omitted to save space

编辑2:我一直在研究Android源代码跟踪异常的来源。这是第456和457行 sendMessageAtTime 在里面 Handler :

msg.target = this;
sent = queue.enqueueMessage(msg, uptimeMillis);

这是 enqueueMessage 从 MessageQueue :

    final boolean enqueueMessage(Message msg, long when) {
        if (msg.when != 0) {
            throw new AndroidRuntimeException(msg
                    + " This message is already in use.");
        }
        if (msg.target == null && !mQuitAllowed) {
            throw new RuntimeException("Main thread not allowed to quit");
        }
        synchronized (this) {
            if (mQuiting) {
                RuntimeException e = new RuntimeException(
                    msg.target + " sending message to a Handler on a dead thread");
                Log.w("MessageQueue", e.getMessage(), e);
                return false;
            } else if (msg.target == null) {
                mQuiting = true;
            }

            msg.when = when;
            //Log.d("MessageQueue", "Enqueing: " + msg);
            Message p = mMessages;
            if (p == null || when == 0 || when < p.when) {
                msg.next = p;
                mMessages = msg;
                this.notify();
            } else {
                Message prev = null;
                while (p != null && p.when <= when) {
                    prev = p;
                    p = p.next;
                }
                msg.next = prev.next;
                prev.next = msg;
                this.notify();
            }
        }
        return true;
    }

我有点困惑 mQuiting 是的,但看起来像上一次 排队消息 被称为 msg.target 是空的。