How to set identifier in MKPointAnnotation - ios

Question

I am trying to make a lot different type of annotation. All annotation need to customize for the beautiful reason.
I know that it need to use viewFor Annotation, but how can I know what kind of the annotation?
func addZoneAnnotation() {
let zoneLocations = ZoneData.fetchZoneLocation(inManageobjectcontext: managedObjectContext!)
for zoneLocation in zoneLocations! {
let zoneCoordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: Double(zoneLocation["latitude"]!)!, longitude: Double(zoneLocation["longitude"]!)!)
let zoneAnnotation = MKPointAnnotation()
zoneAnnotation.coordinate = zoneCoordinate
map.addAnnotation(zoneAnnotation)
}
}

Answer 1

Subclass MKPointAnnotation to add whatever property that you want:
class MyPointAnnotation : MKPointAnnotation {
var identifier: String?
}
Then you can use it as follow:
func addZoneAnnotation() {
let zoneLocations = ZoneData.fetchZoneLocation(inManageobjectcontext: managedObjectContext!)
for zoneLocation in zoneLocations! {
let zoneCoordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: Double(zoneLocation["latitude"]!)!, longitude: Double(zoneLocation["longitude"]!)!)
let zoneAnnotation = MyPointAnnotation()
zoneAnnotation.coordinate = zoneCoordinate
zoneAnnotation.identifier = "an identifier"
map.addAnnotation(zoneAnnotation)
}
}
And finally when you need to access it:
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
guard let annotation = annotation as? MyPointAnnotation else {
return nil
}
var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: "reuseIdentifier")
if annotationView == nil {
annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "reuseIdentifier")
} else {
annotationView?.annotation = annotation
}
// Now you can identify your point annotation
if annotation.identifier == "an identifier" {
// do something
}
return annotationView
}