ios nstimer run in background for check alarm time is equal to current time and play audio

Question

I googled it for hours, but could not find any information if there is any way to keep a running NSTimer active when the app is running in the background ? Please Help me , when app is go to background then one function run and each sec check alarm time is equal to current time , then play audio and open close alarm page If anybody know alarm app open source and its run on background please share with me Here i try this , but this is not working

- (void)applicationDidEnterBackground:(UIApplication *)application
{

    inBackground=YES;
    UIApplication*    app = [UIApplication sharedApplication];

    bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
        [app endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    }];

    // Start the long-running task and return immediately.
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        while (inBackground == YES) {


            [NSTimer scheduledTimerWithTimeInterval:1.0 target:self
                                          selector:@selector(checkAlert) userInfo:nil repeats:YES];

        }


        [app endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    });

}
-(void)checkAlert
{
    NSLog(@"Chalaaaaaa");
    NSString *checkAlarmOnOff = [defaults stringForKey:@"setAlarm"];
    // Switch Alarm From Setting page
    NSString *SwitchAlarm=[defaults stringForKey:@"setSwitchAlarm"];

    if([SwitchAlarm isEqualToString:@"ON"])
    {
        if([checkAlarmOnOff isEqualToString:@"YES"])
        {
            if(![alarmRun isEqualToString:@"Yes"])
            {

                NSString *getAlarmTime = [defaults stringForKey:@"setAlarmTime"];
                 NSLog(@"AA-%@",getAlarmTime);
                 NSLog(@"BB-%@",globalClockTime);
                if([getAlarmTime isEqualToString:globalClockTime])
                {
                    [self MusicAction];

                    [_audioPlayer play];
                    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alarm" message:@"Alarm On" delegate:self cancelButtonTitle:@"Off" otherButtonTitles:nil, nil];
                    [alert show];
                    alarmRun=@"Yes";

                }
            }

        }
    }


}

Please help me,

Answer 1

NSTimer will not run in background. and using beginBackgroundTaskWithExpirationHandler won't save your problem. with background task your app can run max 10 min and then will get killed

you should use UILocalNotification

UILocalNotification *localNotification = [[UILocalNotification alloc] init];
localNotification.fireDate = dateTime;
localNotification.alertBody = [NSString stringWithFormat:@"Alert Fired at %@", dateTime];
localNotification.soundName = UILocalNotificationDefaultSoundName;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];

calculate time with NSCalendar and add this line:

localNotification.repeatInterval = NSDayCalendarUnit;