How to add circle around map pin in Swift? - ios

Question

I've been trying to figure this one out with no luck.
What I can do:
Show user's current location
Show a pin wherever I want (depending on lat and long)
What I can't figure out:
How do I create a geofenced circle around this location?
func setupData() {
// 1. check if system can monitor regions
if CLLocationManager.isMonitoringAvailable(for:
CLCircularRegion.self) {
// 2. region data
let title = "Marina Bar Hop"
let coordinate = CLLocationCoordinate2DMake(33.97823607957177, -118.43823725357653)
let regionRadius = 300.0
// 3. setup region
let region = CLCircularRegion(center: CLLocationCoordinate2D(latitude: coordinate.latitude,
longitude: coordinate.longitude), radius: regionRadius, identifier: title)
locationManager.startMonitoring(for: region)
// 4. setup annotation
let restaurantAnnotation = MKPointAnnotation()
restaurantAnnotation.coordinate = coordinate;
restaurantAnnotation.title = "\(title)";
mapView.addAnnotation(restaurantAnnotation)
// 5. setup circle
let circle = MKCircle(center: coordinate, radius: regionRadius)
mapView.addOverlay(circle)
}
else {
print("System can't track regions")
}
}
// 6. draw circle
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let circleRenderer = MKCircleRenderer(overlay: overlay)
circleRenderer.strokeColor = UIColor.red
circleRenderer.lineWidth = 1.0
return circleRenderer
}
See "draw circle" and "set up circle" ^
In case there's an error I'm not seeing, the rest of the code is here.
Any help is greatly appreciated! I thought I've done everything to solve this issue, but it still won't work. :( Thank you in advance!

Answer 1

The trouble with this question is that the code in the question does not represent faithfully the real code. Fortunately, you also posted the real code:
https://github.com/kcapretta/RadiusSocialNetworkingApp/blob/master/RadiusMap/RadiusLocationViewController
In that version of the code, we see clearly that your delegate method
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay)
-> MKOverlayRenderer {
is buried inside your viewDidLoad. Thus it is purely a local function, invisible to all other code. You need to get it out of there so that it is a method of the view controller.
To demonstrate, here's a slight variant on your code, leaving out the unnecessary stuff about the region monitoring and the user's current location and concentrating just on the annotation and the circle overlay:
class ViewController: UIViewController, MKMapViewDelegate {
#IBOutlet var mapView : MKMapView!
let coordinate = CLLocationCoordinate2DMake(33.97823607957177, -118.43823725357653)
// this is a _method_
override func viewDidLoad() {
super.viewDidLoad()
mapView.delegate = self
mapView.region = MKCoordinateRegion(center: coordinate, latitudinalMeters: 1000, longitudinalMeters: 1000)
let title = "Marina Bar Hop"
let restaurantAnnotation = MKPointAnnotation()
restaurantAnnotation.coordinate = coordinate
restaurantAnnotation.title = title
mapView.addAnnotation(restaurantAnnotation)
let regionRadius = 300.0
let circle = MKCircle(center: coordinate, radius: regionRadius)
mapView.addOverlay(circle)
}
// this is a _method_
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let circleRenderer = MKCircleRenderer(overlay: overlay)
circleRenderer.strokeColor = UIColor.red
circleRenderer.lineWidth = 1.0
return circleRenderer
}
}
The result: