PendingIntent throughout multiple Instances

Question

I have implemented an Alarm class wich should set a new pending Intent and always overriwrite the old one. (I would rather stop/delete all old ones but I dont know how to)

private void startAlarm(){
    Intent intent = new Intent(source, Alarm_Activity.class);
    // 10000 should be the ID of Intent
    PendingIntent pendingIntent = PendingIntent.getActivity(source, 10000, intent, PendingIntent.FLAG_CANCEL_CURRENT);

    AlarmManager am = (AlarmManager)source.getSystemService(Context.ALARM_SERVICE);
    am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),pendingIntent);
}

Unfortionatly I create this class multiple times and from different activities. I think this is the reason why it doesnt cancel the last intent (Flag_cancel_current). How can I make the Flag work throughout multiple instances of this class?

Answer 1

Given your code, so long as all places are using the same Intent (pointing to Alarm_Activity.class) and are using the same PendingIntent ID (10000 in your sample), your code will cancel any current PendingIntent.

This does not cancel any current alarms.

To cancel an alarm, call cancel() on AlarmManager. In particular, if you do this, get rid of PendingIntent.FLAG_CANCEL_CURRENT, so your cancelling of the old PendingIntent does not somehow interfere with your cancelling of the old alarm tied to that PendingIntent.