问题描述
我尝试制作覆盖图，但地图上没有任何显示。
我要绘制4条线，使其形状像正方形，将显示在地图上（我添加了4条CLLocationCoord）。
我在做什么错了？
我试图添加mapView.delegate = self，但是我不知道为什么它不起作用。
导入UIKit
导入MapKit
导入CoreLocation
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()
}
}
解决方法
mapView.delegate = self
在您的类实现MKMapViewDelegate时起作用。
类似
class ViewController: UIViewController,MKMapViewDelegate {