【发布时间】：2020-12-31 16:44:59
【问题描述】：
我尝试制作叠加层，但地图上没有显示任何内容。
我想制作一个 4 条线，形成一个像正方形的形状，这将显示在地图上（我添加了 4 个 CLLocationCoord）。
我做错了什么？
我应该添加一些代码吗？
我尝试添加 mapView.delegate = self 但我不知道为什么它不起作用。
导入 UIKit
导入 MapKit
导入核心位置
class ViewController: UIViewController {
@IBOutlet weak var mapView: MKMapView!
let locationManager = CLLocationManager()
let regionInMeters: Double = 1000
override func viewDidLoad() {
super.viewDidLoad()
checkLocationServices()
//calling the method
addBoundry()
}
func addBoundry(){ //creation of a polygon
var points = [CLLocationCoordinate2DMake(52.284428, 20.989394),
CLLocationCoordinate2DMake(52.224534, 21.044326),
CLLocationCoordinate2DMake(52.209182, 20.948024),
CLLocationCoordinate2DMake(52.247143, 20.918842),]
let polygon = MKPolygon(coordinates: &points, count: points.count)
mapView.addOverlay(polygon)
}
func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer {
if overlay is MKPolygon {
let polygonView = MKPolygonRenderer(overlay: overlay)
polygonView.strokeColor = .magenta
return polygonView
}
return MKOverlayRenderer()
}
func setupLocationManager(){
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
}
func centerViewOnUserLocation () {
if let location = locationManager.location?.coordinate {
let region = MKCoordinateRegion.init(center: location, latitudinalMeters: regionInMeters, longitudinalMeters: regionInMeters)
mapView.setRegion(region, animated: true)
}
}
func checkLocationServices() {
if CLLocationManager.locationServicesEnabled() {
setupLocationManager()
checkLocationAuthorization()
} else {
// Show alert letting the user know they have to turn this on.
}
}
func checkLocationAuthorization() {
switch CLLocationManager.authorizationStatus() {
case .authorizedWhenInUse:
mapView.showsUserLocation = true
centerViewOnUserLocation()
locationManager.startUpdatingLocation()
break
case .denied:
// Show alert instructing them how to turn on perm
break
case .notDetermined:
locationManager.requestWhenInUseAuthorization()
break
case .restricted:
// Show an alert letting them know what's up
break
case .authorizedAlways:
break
}
}
}
extension ViewController: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.last else {return}
let center = CLLocationCoordinate2D(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude)
let region = MKCoordinateRegion.init(center: center, latitudinalMeters: regionInMeters, longitudinalMeters: regionInMeters)
mapView.setRegion(region, animated: true)
}
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
checkLocationAuthorization()
}
}
【问题讨论】：
标签： mapkit overlay polygon swift5 xcode11