Alarm Manager with 2 pending intents only 1 works?

问题:

I have 2 alarms set, one for notifications, and the other one to do some tasks. My problem is that only one alarm seems to work( the notifications service one, the first alarm set). The Other alarm never goes off. Here is my code :

Intent myIntent1 = new Intent(getApplicationContext(), NotificationService.class);
        PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 0, myIntent1, 0);
        AlarmManager alarmManager1 = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
        Calendar calendar1 = Calendar.getInstance();
        calendar1.setTimeInMillis(System.currentTimeMillis());
        long frequency1 = 30 * 1000; // in ms
        alarmManager1.setRepeating(AlarmManager.RTC_WAKEUP, calendar1.getTimeInMillis(), frequency1, pendingIntent);

        // Set alarm to fire go to Next day everyday at the same time
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 14); // For 1 PM or 2 PM
        calendar.set(Calendar.MINUTE, 57);
        calendar.setTimeInMillis(System.currentTimeMillis());
        Intent myintent = new Intent(getApplicationContext(), AlarmNextDayService.class);
        AlarmManager alarmManager = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
        PendingIntent pi = PendingIntent.getService(getApplicationContext(), 11, myintent,0 );
        alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),AlarmManager.INTERVAL_DAY, pi);

Any suggestions are welcome. I have looked atother sources as well nothing works for me till now. I have also added alarm permisison in the manifest file as the following :

<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>

Thank you

回答1:

Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.HOUR_OF_DAY, 14); // For 1 PM or 2 PM
    calendar.set(Calendar.MINUTE, 57);
    calendar.setTimeInMillis(System.currentTimeMillis());

You are setting the HOUR_OF_DAY and the MINUTE but them you override that by calling setTimeInMillis(System.currentTimeMillis());

After that you set the alarm with the calendar.getTimeMillis() value which is already in the past, so the alarm is cancelled I think.

回答2:

You're most likely seeing an issue because a Service is not guaranteed to run when triggered by an alarm, due to power save. If your device is on battery and idle when that alarm goes off, it will not trigger until the next time the device is full on or on AC power. You'll need to use a BroadcastReceiver which holds a wake lock which is then released by the Service when it is done. The WakefulBroadcastReceiver makes this a little easier to handle. This article will help provide more details.