在MapKit Swift3上旋转接点方向

annotationView.transform = CGAffineTransform(rotationAngle: angle)

import MapKit

class CustomAnnotation: NSObject, MKAnnotation {
    var coordinate: CLLocationCoordinate2D
    
    init(coordinate: CLLocationCoordinate2D) {
        self.coordinate = coordinate
    }
}

class ViewController: UIViewController, MKMapViewDelegate {
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        let annotation = CustomAnnotation(coordinate: CLLocationCoordinate2D(latitude: 37.331686, longitude: -122.030656))
        mapView.addAnnotation(annotation)
    }
    
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        if annotation is CustomAnnotation {
            let identifier = "CustomAnnotation"
            var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)
            
            if annotationView == nil {
                annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: identifier)
            } else {
                annotationView?.annotation = annotation
            }
            
            annotationView?.image = UIImage(named: "pin")
            annotationView?.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 4)
            
            return annotationView
        }
        
        return nil
    }
}