How to draw a polygon overlay using MapKit and swift
I'm trying to get the following code to draw a polygon on a map, but it doesn't work for some reason. That I was wrong here?
import UIKit
import MapKit
class ViewController: UIViewController {
@IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
let initialLocation = CLLocation(latitude: 49.140838, longitude: -123.127886)
centerMapOnLocation(initialLocation)
addBoundry()
}
func addBoundry()
{
var points=[CLLocationCoordinate2DMake(49.142677, -123.135139),CLLocationCoordinate2DMake(49.142730, -123.125794),CLLocationCoordinate2DMake(49.140874, -123.125805),CLLocationCoordinate2DMake(49.140885, -123.135214)]
let polygon = MKPolygon(coordinates: &points, count: points.count)
mapView.addOverlay(polygon)
}
let regionRadius: CLLocationDistance = 1000
func centerMapOnLocation(location: CLLocation) {
let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
regionRadius * 2.0, regionRadius * 2.0)
mapView.setRegion(coordinateRegion, animated: true)
}
}
func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
if overlay is MKPolygon {
let polygonView = MKPolygonRenderer(overlay: overlay)
polygonView.strokeColor = UIColor.magentaColor()
return polygonView
}
return nil
}
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It may appear that you have implemented (formerly known as ) as a global function. The method must be in a class definition, or better yet, to keep our code well organized, inside an extension : mapView(_:renderFor:)
rendererForOverlay
ViewController
MKMapViewDelegate
extension ViewController: MKMapViewDelegate {
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
...
}
}
Also make sure you define the view controller as a delegate
map view. This is probably easiest to do in IB, but you can also do it in viewDidLoad
:
mapView.delegate = self
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