Avoid cancelation of Notification on removing app from recent apps list

Question

I'm using below snippet to show a notification from a service inside my app:

NotificationCompat.Builder mBuilder =
        new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.ic_launcher)
                .setContentTitle(currentNotificaion.getMessageTitle())
                .setContentIntent(contentIntent)
                .setContentText(currentNotificaion.getMessageText())
                .setAutoCancel(true);
int mNotificationId = (int) currentNotificaion.getMessageServerID();
// Gets an instance of the NotificationManager service
NotificationManager mNotifyMgr =
        (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
// Builds the notification and issues it.
mNotifyMgr.notify(mNotificationId, mBuilder.build());

My service is declared like this in manifest:

<service
android:name="com.myapp.services.NotificationService"
android:stopWithTask="false">
</service>

But when closing my app from recent apps list, notification is disappear and removed from notification bar. Another things is I'm not going to use stick notifications which are never removed from notification bar.

How can I avoid this?

Answer 1

Inside your Manifest file, keep flag stopWithTask as true for Service. Like:

<service
    android:name="com.myapp.MyService"
    android:stopWithTask="true" />

I just resolved a similar kind of issue.

Here is what you can do if its just about stopping service when application is killed by swiping from Recent app list.

1. Inside your Manifest file, keep flag stopWithTask as true for Service. Like:

But as you say you want to unregister listeners and stop notification etc, I would suggest this approach:

Inside your Manifest file, keep flag stopWithTask as false for Service. Like:

    <service
        android:name="com.myapp.MyService"
        android:stopWithTask="false" />

2. Now in your MyService service, override method onTaskRemoved. (This will be fired only if stopWithTask is set to false).

   public void onTaskRemoved(Intent rootIntent) {
   
   //unregister listeners
   //do any other cleanup if required
   
   //stop service
       stopSelf();  
   }
   

Hope it will help you.

Answer 2

If you want a background service running with a foreground notification, the best way is to use startForeground() function. You can check Android docs here and there are some answers about it in SO also like this from @CommonsWare with example included.

Hope it helps!

Answer 3

If you want to show your notification after your application is killed I would suggest this.

As wrote @JamilHasnineTamim you can catch the event when the application is killed from the device.

<service
        android:name="com.myapp.MyService"
        android:stopWithTask="false" />

inside service

public void onTaskRemoved(Intent rootIntent) {
//your code
//stop service
    stopSelf();  
}

but, inside this code you can charge an AlarmManager to restart your own notification after a few seconds. Put this inside onTaskRemoved:

AlarmManager am = (AlarmManager) ctx.getSystemService(Activity.ALARM_SERVICE);
Intent intent = new Intent(BRNotificator.INTENT_FILTER);
int somealarmnumber = 10000;//or any numbe your want
long nexttime = System.currentTimeInMillis() + 5000L;
PendingIntent pi =PendingIntent.getBroadcast(ctx, somealarmnumber, intent, PendingIntent.FLAG_CANCEL_CURRENT):
am.setAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, nexttime, pi);

where broadcast reciever is:

public class BRNotificator extends WakefulBroadcastReceiver {
    public static final String INTENT_FILTER = "com.example.BRNotificator";
    @Override
    public void onReceive(Context ctx, Intent intent) {
//restart your service this notification
        OWakeLocker.acquire(ctx, 0);
        ComponentName comp = new ComponentName(ctx.getPackageName(),
                YourServiceClass.class.getName());
        startWakefulService(ctx, intent.setComponent(comp));

//or just show your notification again:
NotificationCompat.Builder mBuilder = //... your code to show
    }

}

this is a helper that can help to wake up your device :

public class OWakeLocker {
    private static PowerManager.WakeLock[] wakeLocks = new PowerManager.WakeLock[1];//Services count

    @SuppressWarnings("deprecation")
    public static void acquire(Context ctx, int index) {
        WakeLock wakeLock = wakeLocks[index];
        if (wakeLock != null) wakeLock.release();

        PowerManager pm = (PowerManager) ctx.getSystemService(Context.POWER_SERVICE);
            wakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK |
                    PowerManager.ACQUIRE_CAUSES_WAKEUP |
                    PowerManager.ON_AFTER_RELEASE, _.APPNAME + Integer.toString(index));
        if (wakeLock != null && wakeLock.isHeld()){
            wakeLock.acquire();
        }
    }

    public static void release(int index) {
        WakeLock wakeLock = wakeLocks[index];
        if (wakeLock != null) 
            wakeLock.release();
            wakeLock = null;
    }
}

Answer 4

You can even

public static void clearNotifications(Context context) {
    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.cancelAll();
}

Answer 5

 .setAutoCancel(true);

Let's set this to false, so notification is not canceled and not removed. You can also put

.setOngoing(true)

Update: If above does not work and when notification is send from service, you need to call

 startForeground(int, Notification) 

in order to do not kill service when app gets killed.

From Android documentation:

A started service can use the startForeground(int, Notification) API to put the service in a foreground state, where the system considers it to be something the user is actively aware of and thus not a candidate for killing when low on memory.

More could be found here: Android Service startForeground