Question

I have a MKMapView. I need to add a circle as a radius around the annotation (say 1km out from the position).

I would have assumed this is some form of MKAnnotation, but I can’t find anything in the documentation that explains this. Does anyone know how this is done?

Answer 1

You need to create an MKCircle overlay and set its center coordinate to the same as the annotation.

For example:

//after adding the annotation at "coordinate", add the circle...
MKCircle *circle = [MKCircle circleWithCenterCoordinate:coordinate radius:1000];
[mapView addOverlay:circle];

//implement the viewForOverlay delegate method...    
-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id)overlay 
{
    MKCircleView *circleView = [[[MKCircleView alloc] initWithOverlay:overlay] autorelease];
    circleView.strokeColor = [UIColor redColor];
    circleView.lineWidth = 2;
    return circleView;
}