警报管理器的警报有时不会被取消

Question

我创建并取消一次性警报，代码如下。 有时会发生警报未取消但在定义的时间内触发。字符串 timerType 始终相同。

有人可以解释为什么警报并不总是被取消？

谢谢。 弗朗索瓦

public static final void startOneShotAlarm(Context context, int minutes, String timerType) {

    long period = 1000*60*minutes;
    long firstTime = SystemClock.elapsedRealtime() + period;

    Intent intent = new Intent(context, RepeaterDone.class);
    intent.setData(Uri.parse(timerType));
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent,  PendingIntent.FLAG_ONE_SHOT);

    Log.d("BAN", "RepeaterStart, >" + Uri.parse(timerType) + "< ctx="+context.toString() + "i=" + intent.toString());

    // Schedule the alarm!
    AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
    alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, firstTime, pendingIntent);
}

private static final void stopOneShotAlarm(Context context, String timerType) {
    // Create the same intent, and thus a matching IntentSender, for the one that was scheduled.
    Intent intent = new Intent(context, RepeaterDone.class);
    intent.setData(Uri.parse(timerType));
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent,        PendingIntent.FLAG_ONE_SHOT);
    Log.d("BAN", "stop, >" + Uri.parse(timerType) + "< ctx="+context.toString() + "i=" + intent.toString());            

    // And cancel the alarm.
    AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
    alarmManager.cancel(pendingIntent);
}