I have an activity that shows a notification on notification bar. If the user goes to the background pressing the home button I keep the notification (that's what I need), but when the user closes the application I need to cancel the notification and that's my problem.
How could I deal with this? Every time the user goes background and then close the app I need to remove the notification from the notification bar, but if the user keep the application in background I need the notification.
You have your notification an ID when your created it, right?
Then all you have to do is use that ID to cancel it.
For example:
NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mNotificationManager.cancel(4);
on destroy is fired when they back out of your app or if you call finish() on your activity.