单击“通知”未启动预期活动？

我在我的应用程序中使用 GCM，并在收到 GCM 消息时使用 NotificationManager 创建通知。到目前为止，一切正常，GCM 消息在通知区域中正确显示，但是当我单击通知时，它应该启动一个活动我的应用程序将显示未发生的消息详细信息。每次我单击通知时，它都不会启动任何活动，并且保持原样。我用于创建通知的代码是：

private void sendNotification(String msg) {
        SharedPreferences prefs = getSharedPreferences(
                DataAccessServer.PREFS_NAME, MODE_PRIVATE);
        mNotificationManager = (NotificationManager) this
                .getSystemService(Context.NOTIFICATION_SERVICE);
        Intent intent = new Intent(this, WarningDetails.class);
        Bundle bundle = new Bundle();
        bundle.putString("warning", msg);
        bundle.putInt("warningId", NOTIFICATION_ID);
        intent.putExtras(bundle);
        // The stack builder object will contain an artificial back stack for
        // the
        // started Activity.
        // This ensures that navigating backward from the Activity leads out of
        // your application to the Home screen.
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
        // Adds the back stack for the Intent (but not the Intent itself)
        stackBuilder.addParentStack(WarningDetails.class);
        // Adds the Intent that starts the Activity to the top of the stack
        stackBuilder.addNextIntent(intent);

        PendingIntent contentIntent = stackBuilder.getPendingIntent(0,
                PendingIntent.FLAG_UPDATE_CURRENT);

        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
                this).setSmallIcon(R.drawable.weather_alert_notification)
                .setContentTitle("Weather Notification")
                .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
                .setContentText(msg);
        String selectedSound = prefs.getString("selectedSound", "");
        if (!selectedSound.equals("")) {
            Uri alarmSound = Uri.parse(selectedSound);
            mBuilder.setSound(alarmSound);

        } else {
            Uri alarmSound = RingtoneManager
                    .getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            mBuilder.setSound(alarmSound);
        }

        if (prefs.getBoolean("isVibrateOn", false)) {
            long[] pattern = { 500, 500, 500, 500, 500, 500, 500, 500, 500 };
            mBuilder.setVibrate(pattern);
        }

        mBuilder.setContentIntent(contentIntent);
        mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
    }

我更新了代码以支持Preserving Navigation when Starting an Activity就像使用 Android 开发者网站的 Gmail 应用程序中发生的情况一样，从那时起它就停止工作了。请有人指导我在这段代码中遗漏或做错了什么。

我的问题已经解决了，我只需添加PendingIntent.FLAG_ONE_SHOT标志也是如此，所以我更换了：

PendingIntent contentIntent = stackBuilder
                .getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

to

PendingIntent contentIntent = stackBuilder
                .getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT
                        | PendingIntent.FLAG_ONE_SHOT);