使用真实分辨率将MKMapView渲染为UIImage

import MapKit

class ViewController: UIViewController {
    @IBOutlet weak var mapView: MKMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let center = CLLocationCoordinate2D(latitude: 31.2304, longitude: 121.4737)
        let region = MKCoordinateRegion(center: center, latitudinalMeters: 1000, longitudinalMeters: 1000)
        mapView.setRegion(region, animated: true)
    }
    
    @IBAction func didTapRenderButton(_ sender: Any) {
        let renderer = UIGraphicsImageRenderer(bounds: mapView.bounds)
        let image = renderer.image { context in
            mapView.drawHierarchy(in: mapView.bounds, afterScreenUpdates: true)
        }
        UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
    }
}