Here is an example of foreground service that I use and that works, it remains active when the app is closed. Of course, it also must be started, and for that task the app must be running at a first glance, or a receiver of a boot event must be set, but this is another story.
public class MyService extends Service {
static final int NOTIFICATION_ID = 543;
public static boolean isServiceRunning = false;
@Override
public void onCreate() {
super.onCreate();
startServiceWithNotification();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent != null && intent.getAction().equals(C.ACTION_START_SERVICE)) {
startServiceWithNotification();
}
else stopMyService();
return START_STICKY;
}
// In case the service is deleted or crashes some how
@Override
public void onDestroy() {
isServiceRunning = false;
super.onDestroy();
}
@Override
public IBinder onBind(Intent intent) {
// Used only in case of bound services.
return null;
}
void startServiceWithNotification() {
if (isServiceRunning) return;
isServiceRunning = true;
Intent notificationIntent = new Intent(getApplicationContext(), MyActivity.class);
notificationIntent.setAction(C.ACTION_MAIN); // A string containing the action name
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent contentPendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
Bitmap icon = BitmapFactory.decodeResource(getResources(), R.drawable.my_icon);
Notification notification = new NotificationCompat.Builder(this)
.setContentTitle(getResources().getString(R.string.app_name))
.setTicker(getResources().getString(R.string.app_name))
.setContentText(getResources().getString(R.string.my_string))
.setSmallIcon(R.drawable.my_icon)
.setLargeIcon(Bitmap.createScaledBitmap(icon, 128, 128, false))
.setContentIntent(contentPendingIntent)
.setOngoing(true)
// .setDeleteIntent(contentPendingIntent) // if needed
.build();
notification.flags = notification.flags | Notification.FLAG_NO_CLEAR; // NO_CLEAR makes the notification stay when the user performs a "delete all" command
startForeground(NOTIFICATION_ID, notification);
}
void stopMyService() {
stopForeground(true);
stopSelf();
isServiceRunning = false;
}
}
Then I run it with
Intent startIntent = new Intent(getApplicationContext(), MyService.class);
startIntent.setAction(C.ACTION_START_SERVICE);
startService(startIntent);
Please note the two constants used as Actions, these are Strings that must start with the package name.