Android前台服务通知不持久

Question

I have created a class which extends Service and runs as a foreground service. I would like my service notification to be persistent (ie not removed by swiping). However, my notification can be dismissed by swiping.

The Service documentation states: ...A foreground service must provide a notification for the status bar, which is placed under the Ongoing heading. This means that the notification cannot be dismissed unless the service is either stopped or removed from the foreground...

I did put break points to check whether onDestroy() or stopSelf() is hit, but this is not the case. The service is running in foreground mode, but I can dismiss the notification by swiping.

I have found quite a few questions regarding the opposite case, where it was not possible to dismiss the notification after the service was stopped, but did not find any question similar to my problem.

The service is started via an Intent and initialized as follows:

@Override
public void onCreate()
{
    super.onCreate();

    initialize();
}

private void initialize()
{
    Notification n = get_service_notification();
    startForeground(10, n);

    LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver, new IntentFilter(BroadcastCodes.service_broadcast_intent_name));
}

@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
    startServing();
    return START_STICKY;
}

where startServing() subscribes to location updates

The notification is built like this

private Notification get_service_notification()
{
    Intent intent = new Intent(this, LoginActivity.class);
    PendingIntent contentIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

    NotificationCompat.Builder b = new NotificationCompat.Builder(this);

    b.setAutoCancel(false)
            .setWhen(System.currentTimeMillis())
            .setSmallIcon(R.drawable.app_icon)
            .setTicker("some text")
            .setContentTitle("some text")
            .setContentText("some text")
            .setContentIntent(contentIntent)
            .setContentInfo("")
            .setOngoing(true);

    Notification res = b.build();
    res.flags |= Notification.FLAG_ONGOING_EVENT | Notification.FLAG_NO_CLEAR;

    return res;
}

I have tried playing around with the flags and setOngoing/setAutoCancel, but the result stayed the same.

SDK versions are configured as minSdkVersion 18, targetSdkVersion 25

I would really appreciate any input regarding this issue - it might be just some stupid mistake, but I already did spend more than a few hours trying to research on my own...unfortunately to no avail.

EDIT 1

I still have not figured out the problem. I decided to try a dirty hack, but still no luck.

I made a PendingIntent and registered it via setDeleteIntent() the idea being to display a new notification once this one was dismissed by swipe. Unfortunately, I was not able to get this to work (the intent never fires when swiping).

I would also like to clarify, that the notification CAN BE swiped away, but IS NOT AFFECTED (ie is not deleted) by the clear-all button in the notification pane (the trash icon).

EDIT 2

As mentioned above I was not able to use setDeleteIntent() to recreate my notification when it is dismissed by swipe.

For now I settled with a workaround - my service does some periodical tasks. I am now calling

notificationManager.notify(10, service_notification);

when my task runs so that even if swiped away, my notification will be recreated after a while.

I still have a strong feeling that I just misread the documentation, since there are several notifications on my test device (Honor API23) that can not be swiped away.

EDIT 3

I have tried the same code on a different device (Lenovo API23) and the notification works as expected (can not be dismissed and can not be swiped). My problem seems to be device specific.

Answer 1

I made a few further tests (besides the ones mentioned in updates). I tried running various examples/tutorials from around the internet like this page here

On the Honor I was initially running my tests the notification could always be swiped, on the Lenovo and others the "ongoing" flag works as stated in the documentation, ie it can not be dismissed via swipe action.

To sum it up, my problem really seems to be device specific.