Circle overlay follow user location - objective-c

Question

How can i make my custom circle overlay follow as a subview the current user location in real time? I have managed to display my circle overlay and get to the center of userlocation but when user moves (gps) the overlay stays still and does not followuser. How do i fix that? Thank you in advance..
- (void)viewDidLoad {
[super viewDidLoad];
[self.mapView setRegion:MKCoordinateRegionMake(self.location.coordinate, MKCoordinateSpanMake(0.02, 0.02))];
[self configureOverlay];
[[self locationManager] startUpdatingLocation];
}
in configureOverlay:
CircleOverlay *overlay = [[CircleOverlay alloc] initWithCoordinate:self.location.coordinate radius:self.radius];
[self.mapView addOverlay:overlay];
GeoQueryAnnotation *annotation = [[GeoQueryAnnotation alloc] initWithCoordinate:self.location.coordinate radius:self.radius];
[self.mapView addAnnotation:annotation];
I also tried using:
CLLocation *location = _locationManager.location;
CLLocationCoordinate2D coordinate = [location coordinate];
and replacing coordinate with self.location.coordinate
any advise would be appreciated.Thank you

Answer 1

Tell your class you are going to implement CLLocationManagerDelegate
#interface YourClass () <CLLocationManagerDelegate>
Then add the following methods:
#pragma mark CLLocationManagerDelegate Methods
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
//You can change the overlay coordinates here. Even with an animation if you want.
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
NSString *errorType = (error.code == kCLErrorDenied) ? #"Access Denied" : #"Unknown Error";
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error getting Location"message:errorType delegate:nil cancelButtonTitle:#"Okay" otherButtonTitles:nil];
[alert show];
}
The locationManager:didUpdateToLocation... method will be triggered each time the location manager detects a change in the user's position.
Cheers.
EDIT
I forgot about something very important. In your viewDidLoad method add your class as the delegate:
self.locationmanager.delegate = self;