Fixed by using this:
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle("Sound Asleep")
.setContentText("Click to play and stop sounds");
// Creates an explicit intent for an Activity in your app
final Intent notificationIntent = new Intent(this, MainActivity.class);
notificationIntent.setAction(Intent.ACTION_MAIN);
notificationIntent.addCategory(Intent.CATEGORY_LAUNCHER);
// The stack builder object will contain an artificial back stack for the
// started Activity.
// This ensures that navigating backward from the Activity leads out of
// your application to the Home screen.
// Adds the back stack for the Intent (but not the Intent itself)
PendingIntent resultPendingIntent = PendingIntent.getActivity(this,0,notificationIntent,PendingIntent.FLAG_UPDATE_CURRENT);
mBuilder.setContentIntent(resultPendingIntent);
NotificationManager mNotificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
int mId = 0;
// mId allows you to update the notification later on.
mNotificationManager.notify(mId, mBuilder.build());
}
In Manifest
android:launchMode="singleTop"