So überprüfen Sie, ob die Benachrichtigung in Android angezeigt wird

NotificationManager mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
StatusBarNotification[] notifications = mNotificationManager.getActiveNotifications();
for (StatusBarNotification notification : notifications) {
  if (notification.getId() == 100) {
    // Do something.
  }
}
Mohamed Boumlyk