iPhone 的 MapKit 是否可以实现图块叠加

MapKit中的图块叠加功能

swift
import UIKit
import MapKit
class CustomOverlay: NSObject, MKOverlay {
    var coordinate: CLLocationCoordinate2D = CLLocationCoordinate2D()
    var boundingMapRect: MKMapRect = MKMapRect()
    
    init(coordinate: CLLocationCoordinate2D, boundingMapRect: MKMapRect) {
        self.coordinate = coordinate
        self.boundingMapRect = boundingMapRect
    }
    
    func intersectsMapRect(mapRect: MKMapRect) -> Bool {
        return MKMapRectIntersectsRect(boundingMapRect, mapRect)
    }
}
class CustomOverlayView: MKOverlayView {
    override func drawMapRect(mapRect: MKMapRect, zoomScale: MKZoomScale, inContext context: CGContext) {
        let rect = self.rectForMapRect(mapRect)
        let image = UIImage(named: "custom_overlay.png")
        image?.drawInRect(rect)
    }
}
class ViewController: UIViewController, MKMapViewDelegate {
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        let coordinate = CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194)
        let span = MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1)
        let region = MKCoordinateRegion(center: coordinate, span: span)
        mapView.setRegion(region, animated: true)
        
        let overlay = CustomOverlay(coordinate: coordinate, boundingMapRect: mapView.visibleMapRect)
        mapView.addOverlay(overlay)
    }
    
    func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer {
        if overlay is CustomOverlay {
            return CustomOverlayView(overlay: overlay)
        }
        return MKOverlayRenderer(overlay: overlay)
    }
}