如何在SwiftUI中以编程方式计算MKMapCamera centerCoordinateDistance

func calculateCamera(centerCoordinate: CLLocationCoordinate2D, fieldOfView: CLLocationDistance) -> MKMapCamera {
    let distance = fieldOfView / 2 / tan(.pi / 180 * fieldOfView / 2)
    let camera = MKMapCamera(lookingAtCenter: centerCoordinate, fromDistance: distance, pitch: 0, heading: 0)
    return camera
}

struct ContentView: View {
    let centerCoordinate = CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194) // 设置地图的中心坐标
    let fieldOfView: CLLocationDistance = 1000 // 设置相机的视角
    
    var body: some View {
        Map(coordinateRegion: .constant(MKCoordinateRegion(center: centerCoordinate, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))), interactionModes: .all, showsUserLocation: false, userTrackingMode: .none, annotationItems: []) { _ in
            // 设置地图的相机
            calculateCamera(centerCoordinate: centerCoordinate, fieldOfView: fieldOfView)
        }
    }
}