Draw a circle of 1000m radius around users location in MKMapView

Question

(Using iOS 5 and Xcode 4.2)

I have an MKMapView and want to draw a circle of 1000m radius around the user location.

On the surface it would seem tha

Answer 1

I didn't understand benwad answer. So here is clearer answer:

It's pretty easy to add a circle. Conform to MKMapViewDelegate

@interface MyViewController : UIViewController 
@property (weak, nonatomic) IBOutlet MKMapView *mapView;
@end

In viewDidLoad, Create a circle annotation and add it to the map:

CLLocationCoordinate2D center = {39.0, -74.00};

// Add an overlay
MKCircle *circle = [MKCircle circleWithCenterCoordinate:center radius:150000];
[self.mapView addOverlay:circle];

Then implement mapView:viewForOverlay: to return the view.

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id)overlay
{
    MKCircleView *circleView = [[MKCircleView alloc] initWithOverlay:overlay];
    [circleView setFillColor:[UIColor redColor]];
    [circleView setStrokeColor:[UIColor blackColor]];
    [circleView setAlpha:0.5f];
    return circleView;
}

But if you want the circle to always be the same size, no matter the zoom level, you'll have to do something different. Like you say, in regionDidChange:animated:, get the latitudeDelta, then create a new circle (with a radius that fits into the width), remove the old one and add the new one.

Note from me: don't forget to connect mapview with your view controller delegate. Otherwise viewForOverlay won't be called.