折线未在MapKit中显示[Xcode 9.0 - Swift 4.0]

Question

我做了一个视图控制器，一旦打开视图就跟踪我的位置。按下routeButton后，我想要显示蓝色折线。但事实并非如此。我设置了代理并编写了渲染函数，但它仍然没有显示。计算方向时我没有收到错误。它确实运行self.map.add(route.polyline, level: .aboveRoads)线。但是没有折线添加到地图中。我已经在这里阅读了与此相关的多个问题，但没有任何问题可以解决我的问题。任何帮助将不胜感激。

继承我的代码：

class ThirdViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate{


var startLocCoord = CLLocation()
var endLocCoord = CLLocation()



func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
       let location = locations[0]
       let span:MKCoordinateSpan = MKCoordinateSpanMake(0.05,0.05)
        let myLocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude,location.coordinate.longitude)
        let region:MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span)
        map.setRegion(region, animated: true)
        self.map.showsUserLocation = true
        }   



 @IBAction func routeButton (_ sender: Any) {   
    let destinationLoc = CLLocationCoordinate2D(latitude: endLocCoord.coordinate.latitude, longitude: endLocCoord.coordinate.longitude)
        let sourceLoc = CLLocationCoordinate2D(latitude: startLocCoord.coordinate.latitude, longitude: startLocCoord.coordinate.longitude)
        let sourcePlaceMark = MKPlacemark(coordinate: sourceLoc)
        let destinationPlaceMark = MKPlacemark(coordinate: destinationLoc)

        let directionRequest = MKDirectionsRequest()
        directionRequest.source = MKMapItem(placemark: sourcePlaceMark)
        directionRequest.destination = MKMapItem(placemark: destinationPlaceMark)
        directionRequest.transportType = .automobile

        let directions = MKDirections(request: directionRequest)
        directions.calculate { (response, error) in
            guard let directionResponse = response else {
                if let error = error {
                    print("Error with directions==\(error.localizedDescription)")
                }
                return
            }
            let route = directionResponse.routes[0]
            print("route ------->", route)
            self.map.add(route.polyline, level: .aboveRoads)
            let rect = route.polyline.boundingMapRect
            self.map.setRegion(MKCoordinateRegionForMapRect(rect), animated: true)
            print(self.srcLat, self.srcLon, self.lat, self.long)
 }


override func viewDidLoad() {

    manager.desiredAccuracy = kCLLocationAccuracyBest
    UIApplication.shared.isIdleTimerDisabled = true
    manager.delegate = self
    manager.requestWhenInUseAuthorization()
    manager.startUpdatingLocation()
    manager.allowsBackgroundLocationUpdates = true
    manager.pausesLocationUpdatesAutomatically = false
    self.map.isZoomEnabled = false
    self.map.isScrollEnabled = false
    self.map.delegate = self
    map.mapType = MKMapType.standard
}



func mapView(_mapView: MKMapView, rendererFor overlay: MKOverlay)-> MKOverlayRenderer{
    let renderer = MKPolylineRenderer(overlay: overlay)
    renderer.strokeColor = UIColor.blue
    renderer.lineWidth = 5.0
    print("render called")
    return renderer
}


}

谢谢

Answer 1

这可能只是一个错字。更换

func mapView(_mapView: MKMapView, rendererFor overlay: MKOverlay)-> MKOverlayRenderer{

同

func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {