Drag Custom Annotation View

I have my CoreData custom Annotation class:

extension Annotation: MKAnnotation {

    public var coordinate: CLLocationCoordinate2D {
        let cllCoordinate = CLLocationCoordinate2D(latitude: self.latitude, longitude: self.longitude)
        return cllCoordinate
    }

    public var title: String? {
        return self.objectId
    }

    class func keyPathsForValuesAffectingCoordinate() -> Set<String> {
        return Set<String>([ #keyPath(latitude), #keyPath(longitude) ])
    }

    @nonobjc public class func fetchRequest() -> NSFetchRequest<Annotation> {
        return NSFetchRequest<Annotation>(entityName: "Annotation")
    }

    @NSManaged public var latitude: Double
    @NSManaged public var longitude: Double
    @NSManaged public var dateTime: Date
    @NSManaged public var type: String
    @NSManaged public var objectId: String?

}

combined with a fetchedResultsController adding and deleting annotations works fine. But now a want to drag an annotation to another position. But only with setting isDraggable to true is not all. I can’t find newer descriptions how this could be integrated.

Here my viewFor method:

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

    guard annotation is Annotation else { return nil }

    let identifier = "Annotation"
    var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)

    if annotationView == nil {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: identifier)
        annotationView?.isDraggable = true
        annotationView?.canShowCallout = true
    } else {
        annotationView!.annotation = annotation
    }

    let customAnno = annotation as! Annotation
    let image = UIImage(named: customAnno.type)
    annotationView!.image = image

    return annotationView
}

What else do i need? I want to press on the annotation, stay pressed and go to another position, then release the finger and the annotation stays there.

When it drags, it needs to change the coordinate of the underlying annotation. It can’t do that if it’s read-only. So, if you want to make it draggable, you must give the coordinate property a setter:

public var coordinate: CLLocationCoordinate2D {
    get {
        CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    }
    set {
        latitude = newValue.latitude
        longitude = newValue.longitude
    }
}