Custom Image on MKPointAnnotation - swift

Question

I'd like to replace the default MKPointAnnotation logo with a custom one.
So I wrote this code in my MapViewController:
import UIKit
import MapKit
import CoreLocation
class MapViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
#IBOutlet weak var myMap: MKMapView!
let locationManager = CLLocationManager()
var monPin:CustomPointAnnotation!
var pinAnnotationView:MKPinAnnotationView!
override func viewDidLoad() {
super.viewDidLoad()
//Mark: - Authorization
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
locationManager.startUpdatingLocation()
myMap.delegate = self
myMap.mapType = MKMapType.standard
myMap.showsUserLocation = true
let location = CLLocationCoordinate2D(latitude: 43.2885108, longitude:5.3855545000000124)
let center = location
let region = MKCoordinateRegionMake(center, MKCoordinateSpan(latitudeDelta: 0.025, longitudeDelta: 0.025))
myMap.setRegion(region, animated: true)
monPin = CustomPointAnnotation()
monPin.pinCustomImageName = "mapIcon"
monPin.coordinate = location
monPin.title = "Mon titre"
monPin.subtitle = "mon Sous titre"
pinAnnotationView = MKPinAnnotationView(annotation: monPin, reuseIdentifier: "pin")
myMap.addAnnotation(pinAnnotationView.annotation!)
}
//MARK: - Custom Annotation
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
let reuseIdentifier = "pin"
var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier:reuseIdentifier)
if annotationView == nil {
annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
annotationView?.canShowCallout = true
} else {
annotationView?.annotation = annotation
}
let customPointAnnotation = annotation as! CustomPointAnnotation
annotationView?.image = UIImage(named: customPointAnnotation.pinCustomImageName)
return annotationView
}
Where monPin.pinCustomImageName = "mapIcon" refer to my xassets
But it only display a classic MKPointAnnotation picture (this one: https://i.stack.imgur.com/pD82c.png)
**And I think the problem is that: ** the function mapView is not called anywhere because I tried a simple print("hello") in it and it does not appear in the console and even if I erase all this function code, it does not change anything to my app.
That's why I'm wondering how I could face this problem.
I don't understand 100% of my code because I took it from a kind stack overflow user, I mean I understand all the code except the mapView() part.

Answer 1

I believe Xcode has shown a warning if you have created a new project with default settings. (You should not ignore any of the warnings.)
Instance method 'mapView(mapView:viewForAnnotation:)' nearly matches
optional requirement 'mapView(_:viewFor:)' of protocol
'MKMapViewDelegate'
This line of your code:
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
does not implement any of the protocol methods declared in MKMapViewDelegate in Swift 3.
And the quick fix feature (choose the first one) fixes it as:
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
If your Xcode does not help you fix if, you may need to make it by yourself.
Anyway, with the fix shown above, the method should be called.