iOS App Mapview Line Draw - swift3

Question

Having problem in displaying polyline on the mapview
Following this tutorial
MapView Tutorial
Attached is my code.
Annotation is appearing on the map but unable to call the renderer method. Though the delegate is there.
Main Problem: Unable to draw line between two coordinates
Console Output: 2017-02-06 22:54:56.770584 MapTest[2329:805733] [LogMessageLogging] 6.1 Unable to retrieve CarrierName. CTError: domain-2, code-5, errStr:((os/kern) failure)
Here is the code
import UIKit
import MapKit
class ViewController: UIViewController,MKMapViewDelegate {
#IBOutlet weak var myMap: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
// 1.
myMap.delegate = self
// 2.
let sourceLocation = CLLocationCoordinate2D(latitude: 40.759011, longitude: -73.984472)
let destinationLocation = CLLocationCoordinate2D(latitude: 40.748441, longitude: -73.985564)
// 3.
let sourcePlacemark = MKPlacemark(coordinate: sourceLocation, addressDictionary: nil)
let destinationPlacemark = MKPlacemark(coordinate: destinationLocation, addressDictionary: nil)
// 4.
let sourceMapItem = MKMapItem(placemark: sourcePlacemark)
let destinationMapItem = MKMapItem(placemark: destinationPlacemark)
// 5.
let sourceAnnotation = MKPointAnnotation()
sourceAnnotation.title = "Times Square"
if let location = sourcePlacemark.location {
sourceAnnotation.coordinate = location.coordinate
}
let destinationAnnotation = MKPointAnnotation()
destinationAnnotation.title = "Empire State Building"
if let location = destinationPlacemark.location {
destinationAnnotation.coordinate = location.coordinate
}
// 6.
self.myMap.showAnnotations([sourceAnnotation,destinationAnnotation], animated: true )
// 7.
let directionRequest = MKDirectionsRequest()
directionRequest.source = sourceMapItem
directionRequest.destination = destinationMapItem
directionRequest.transportType = .automobile
// Calculate the direction
let directions = MKDirections(request: directionRequest)
// 8.
directions.calculate {
(response, error) -> Void in
guard let response = response else {
if let error = error {
print("Error: \(error)")
}
return
}
let route = response.routes[0]
self.myMap.add((route.polyline), level: MKOverlayLevel.aboveRoads)
let rect = route.polyline.boundingMapRect
self.myMap.setRegion(MKCoordinateRegionForMapRect(rect), animated: true)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer {
print("Line 85 is being called......start...")
let renderer = MKPolylineRenderer(overlay: overlay)
renderer.strokeColor = UIColor.red
renderer.lineWidth = 4.0
print("Line 85 is being called.......end..")
return renderer
}
}

Answer 1

Your rendererForOverlay function has the wrong syntax; Xcode told me this when testing your code. Use
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer
Instead, and a line will be drawn between the two points.