如何在全球地图iOS Swift上添加叠加到MKMapView

import MapKit

let mapView = MKMapView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
view.addSubview(mapView)

let initialLocation = CLLocation(latitude: 37.7749, longitude: -122.4194) // 设置初始位置的经纬度
let regionRadius: CLLocationDistance = 1000 // 设置显示区域的半径（单位：米）

let coordinateRegion = MKCoordinateRegion(center: initialLocation.coordinate, latitudinalMeters: regionRadius, longitudinalMeters: regionRadius)
mapView.setRegion(coordinateRegion, animated: true)

class CustomOverlay: NSObject, MKOverlay {
    var coordinate: CLLocationCoordinate2D
    var boundingMapRect: MKMapRect
    
    init(coordinate: CLLocationCoordinate2D, boundingMapRect: MKMapRect) {
        self.coordinate = coordinate
        self.boundingMapRect = boundingMapRect
    }
}

class CustomOverlayRenderer: MKOverlayRenderer {
    override func draw(_ mapRect: MKMapRect, zoomScale: MKZoomScale, in context: CGContext) {
        // 在这里进行叠加图层的绘制操作
    }
}

let overlayCoordinate = CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194) // 叠加图层的经纬度
let overlayRect = MKMapRect(x: 0, y: 0, width: 1000, height: 1000) // 叠加图层的矩形范围

let customOverlay = CustomOverlay(coordinate: overlayCoordinate, boundingMapRect: overlayRect)
mapView.addOverlay(customOverlay)

extension ViewController: MKMapViewDelegate {
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        if overlay is CustomOverlay {
            return CustomOverlayRenderer(overlay: overlay)
        }
        return MKOverlayRenderer(overlay: overlay)
    }
}