Swift 用于在图像下显示图像和文本的自定义类MKAnnotation

我为MKAnnotation实现了一个自定义类。不幸的是，我仍然不知道如何在图像下显示文本？我也试过使用mkmarkernotationview，一切正常，但不幸的是，您无法在那里更改图像。我需要更改注释的图像和文本。请帮忙！我怎样才能解决我的问题

class ImageAnnotation : NSObject, MKAnnotation {
    var coordinate: CLLocationCoordinate2D
    var title: String?
    var subtitle: String?
    var image: UIImage?
    var colour: UIColor?
    var id : Int?
    var type: String!

    override init() {
        self.coordinate = CLLocationCoordinate2D()
        self.title = nil
        self.subtitle = nil
        self.image = nil
        self.colour = UIColor.white
    }
}

class ImageAnnotationView: MKAnnotationView {
    private var imageView: UIImageView!

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)

        self.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
        self.imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
        self.addSubview(self.imageView)

        self.imageView.layer.cornerRadius = 5.0
        self.imageView.layer.masksToBounds = true
    }

    override var image: UIImage? {
        get {
            return self.imageView.image
        }

        set {
            self.imageView.image = newValue
        }
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

   func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
            if annotation.isKind(of: MKUserLocation.self) {
                return nil
            }
    
        if !annotation.isKind(of: ImageAnnotation.self) {  //Handle non-ImageAnnotations..
                    var pinAnnotationView = mapView.dequeueReusableAnnotationView(withIdentifier: "DefaultPinView")
                    if pinAnnotationView == nil {
                        pinAnnotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "DefaultPinView")
                    }
                    return pinAnnotationView
                }
        
                var view: ImageAnnotationView? = mapView.dequeueReusableAnnotationView(withIdentifier: "imageAnnotation") as? ImageAnnotationView
                if view == nil {
                    view = ImageAnnotationView(annotation: annotation, reuseIdentifier: "imageAnnotation")
                }

                let annotation = annotation as! ImageAnnotation
                view?.image = UIImage(named: "point8")
        
        
                view?.annotation = annotation

                return view
    }