Android Alarm Manager not working with specific date and time

问题

So I have been working on medication intake app, where I need to remind the user locally ( no internet/push notification needed) about taking their medication. I am using Android Alarm manager for this. Below is the code Note I am trying to schedule the alarm for a specific date: "13 July 2018 at 3h30 PM". I schedule and wait but the reminder didn't fire (so not broadcast) however if I used AlarmManager.ELAPSED_REALTIME_WAKEUP with a defined amount of millisecond it does fire ( but AlarmManager.RTC_WAKEUP just does not work) `

    AlarmManager manager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
    Intent myIntent;
    PendingIntent pendingIntent;
    long reminderDateTimeInMilliseconds = 000;

    myIntent = new Intent(this,MedicationScheduleBroadCastReceiver.class);

    pendingIntent = PendingIntent.getBroadcast(this,0,myIntent,PendingIntent.FLAG_UPDATE_CURRENT);

    //TODO : Reminder the user to take medication on the 13th July 2018 at 15:30
    Calendar calendarToSchedule = Calendar.getInstance();

    calendarToSchedule.set(Calendar.YEAR, 2018);
    calendarToSchedule.set(Calendar.MONTH, 07);
    calendarToSchedule.set(Calendar.DAY_OF_MONTH, 13);
    calendarToSchedule.set(Calendar.HOUR_OF_DAY, 15);
    calendarToSchedule.set(Calendar.MINUTE, 30);

    reminderDateTimeInMilliseconds = calendarToSchedule.getTimeInMillis();

    if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O){

        manager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, reminderDateTimeInMilliseconds, pendingIntent);
    }
    else{

        manager.set(AlarmManager.RTC_WAKEUP, reminderDateTimeInMilliseconds, pendingIntent);
    }

`

回答1:

So I figure out the issue, the main issue was the calendar month in Java is actually 0 index based so ( Jan:0 - Dec:11) so below is the updated code.

AlarmManager manager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
Intent myIntent;
PendingIntent pendingIntent;
long reminderDateTimeInMilliseconds = 000;

myIntent = new Intent(this,MedicationScheduleBroadCastReceiver.class);

pendingIntent = PendingIntent.getBroadcast(this,0,myIntent,PendingIntent.FLAG_UPDATE_CURRENT);

//TODO : Reminder the user to take medication on the 13th July 2018 at 15:30
// Note: For the month of July the int value will actuall be 6 instead of 7
Calendar calendarToSchedule = Calendar.getInstance();
calendarToSchedule.setTimeInMillis(System.currentTimeMillis());
calendarToSchedule.clear();

//.Set(Year, Month, Day, Hour, Minutes, Seconds);
calendarToSchedule.set(2018, 06, 13, 15, 30, 0);


reminderDateTimeInMilliseconds = calendarToSchedule.getTimeInMillis();

if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O){

    manager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, reminderDateTimeInMilliseconds, pendingIntent);
}
else{

    manager.set(AlarmManager.RTC_WAKEUP, reminderDateTimeInMilliseconds, pendingIntent);
}

回答2:

Alarms are not fired if device is in Doze mode. Use setAndAllowWhileIdle or setExactAndAllowWhileIdle for alarms to be fired in Doze mode also.

From the Android Doc.

Network access is suspended.
The system ignores wake locks.
Standard AlarmManager alarms (including setExact() and setWindow()) are deferred to the next maintenance window. If you need to set alarms that fire while in Doze, use setAndAllowWhileIdle() or setExactAndAllowWhileIdle().
Alarms set with setAlarmClock() continue to fire normally — the system exits Doze shortly before those alarms fire.
The system does not perform Wi-Fi scans.
The system does not allow sync adapters to run. The system does not allow JobScheduler to run.

来源：https://stackoverflow.com/questions/51324536/android-alarm-manager-not-working-with-specific-date-and-time

标签

java

android

alarmmanager

android-alarms