set region

-(void)viewDidAppear:(BOOL)animated{    

    //new region

    //regionMonitoring

    if ([CLLocationManager regionMonitoringAvailable]){

        NSNumber *eventLatitude = [event latitude];

        NSNumber *eventLongitude = [event longitude];

        

        CLLocation *pinLocation = [[CLLocation alloc]initWithLatitude:[eventLatitude doubleValue] longitude:[eventLongitude doubleValue]];

        CLLocationCoordinate2D location = pinLocation.coordinate;

        CLRegion *region = [[CLRegion alloc]initCircularRegionWithCenter:location radius:10.0 identifier:@"onePin"];

        [locationManager startMonitoringForRegion:region];

    }else{

        NSLog(@"Can't report monitoring");

    }

}

-(void)viewDidDisappear:(BOOL)animated{

    NSLog(@"delete region");

    //delete old region

    for (CLRegion *monitor in [locationManager monitoredRegions]){

        [locationManager stopMonitoringForRegion:monitor];

    }

}

-(void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region{

    NSLog(@"entered region, %f, %f",region.center.latitude, region.center.longitude);

    

    UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"Arrived!" message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];

    [alertView show];

    

    for (CLRegion *monitor in [locationManager monitoredRegions]){

        [locationManager stopMonitoringForRegion:monitor];

    }
}

- (void)locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error
{

    NSLog(@"fail monitoring, %@", error);

}

[self.mapView setUserTrackingMode:MKUserTrackingModeFollow animated:NO];

//heading

    if( [CLLocationManager locationServicesEnabled]

       &&  [CLLocationManager headingAvailable]) {

        [locationManager startUpdatingLocation];

        [locationManager startUpdatingHeading];

        locationManager.headingFilter = 1;

    }else {

        NSLog(@"Can't report heading");

    }