3
我想提請當前用戶位置的折線來註釋一點,但它似乎並沒有畫任何東西:繪製折線與mapkit斯威夫特3
@IBAction func myButtonGo(_ sender: Any) {
showRouteOnMap()
}
func showRouteOnMap() {
let request = MKDirectionsRequest()
request.source = MKMapItem(placemark: MKPlacemark(coordinate: CLLocationCoordinate2D.init(), addressDictionary: nil))
request.destination = MKMapItem(placemark: MKPlacemark(coordinate: (annotationCoordinatePin?.coordinate)!, addressDictionary: nil))
request.requestsAlternateRoutes = true
request.transportType = .automobile
let directions = MKDirections(request: request)
directions.calculate { [unowned self] response, error in guard let unwrappedResponse = response else { return }
if (unwrappedResponse.routes.count > 0) {
self.mapView.add(unwrappedResponse.routes[0].polyline)
self.mapView.setVisibleMapRect(unwrappedResponse.routes[0].polyline.boundingMapRect, animated: true)
}
}
}
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let renderer = MKPolylineRenderer(polyline: overlay as! MKPolyline)
renderer.strokeColor = UIColor.black
return renderer
}
我試圖在調試模式下,它運行在線處斷點處停止:
directions.calculate { [unowned self] response, error in guard let unwrappedResponse = response else { return }
這個錯誤的原因是什麼?