MapKit Direction to Selected annotation - ios

Question

Trying to get direction to selected annotation on the map from the current location of the User but not sure how to catch selected annotation(when user selecting one of them) and show direction.Checked different topics on the Stack but there is not a lot of fresh information about how catch selected annotation and show direction for user location.Please advise.
import UIKit
import MapKit
import CoreLocation
class NavigationVC: UIViewController {
#IBOutlet weak var mapView: MKMapView!
let manager = CLLocationManager()
let request = MKLocalSearchRequest()
override func viewDidLoad() {
super.viewDidLoad()
manager.delegate = self
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestWhenInUseAuthorization()
manager.startUpdatingLocation()
}
}
//MARK: CONFIGURATION OF MAPVIEW
extension NavigationVC: CLLocationManagerDelegate {
func locationManager(_ manager: CLLocationManager, didUpdateLocations
locations: [CLLocation]) {
let location = locations[0]
let span: MKCoordinateSpan = MKCoordinateSpanMake(0.1, 0.1 )
let userLocation:CLLocationCoordinate2D =
CLLocationCoordinate2DMake(location.coordinate.latitude,
location.coordinate.longitude)
let region: MKCoordinateRegion =
MKCoordinateRegionMake(userLocation, span)
mapView.setRegion(region, animated: true)
self.mapView.showsUserLocation = true
request.naturalLanguageQuery = "Currency exchange"
request.region = mapView.region
let activeSearch = MKLocalSearch(request: request)
activeSearch.start { (response, error) in
guard let response = response else {
return
}
for item in response.mapItems {
let annotation = MKPointAnnotation()
annotation.coordinate = item.placemark.coordinate
annotation.title = item.name
DispatchQueue.main.async {
self.mapView.addAnnotation(annotation)
}
}
}
}
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) ->
MKOverlayRenderer {
let polylineRenderer = MKPolylineRenderer(overlay: overlay)
polylineRenderer.strokeColor = UIColor.blue
polylineRenderer.fillColor = UIColor.red
polylineRenderer.lineWidth = 2
return polylineRenderer
}
}

Answer 1

To get the path on the map from your position to the annotation follow this code:
annotation = MKPointAnnotation()
annotation.coordinate = CLLocationCoordinate2D(latitude: CLLocationDegrees(lat),longitude: CLLocationDegrees(lon))
self.map?.addAnnotation(annotation)
var route : MKRoute? = nil
DispatchQueue.global(qos: .userInitiated).async { [weak self] in
let directionRequest = MKDirectionsRequest()
directionRequest.source = MKMapItem.forCurrentLocation();
directionRequest.destination = MKMapItem(placemark: MKPlacemark(coordinate:(self?.annotation.coordinate)!))
directionRequest.transportType = .automobile
let directions = MKDirections(request: directionRequest)
directions.calculate {
(response, error) -> Void in
guard let response = response else {
if let error = error {
print("Error: \(error)")
}
return
}
route = response.routes[0]
if let percorso = route{
DispatchQueue.main.async { [weak self] in
self?.map?.add((percorso.polyline), level: MKOverlayLevel.aboveRoads)
}
}
}
}
You have only to select the correct annotation, maybe try to register a touch listener on the annotation.

Answer 2

Use didSelect delegate method.
e.g.
func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
guard let annotation = view.annotation else {
return
}
let directionRequest = MKDirectionsRequest()
directionRequest.source = MKMapItem.forCurrentLocation()
directionRequest.destination = MKMapItem(placemark: MKPlacemark(coordinate: annotation.coordinate))
directionRequest.transportType = .automobile
let directions = MKDirections(request: directionRequest)
directions.calculate {
(response, error) -> Void in
guard let response = response else {
if let error = error {
print("Error: \(error)")
}
return
}
if !response.routes.isEmpty {
let route = response.routes[0]
DispatchQueue.main.async { [weak self] in
self?.mapView.add(route.polyline)
}
}
}
}
Don't forget guard to prevent crash.
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) ->
MKOverlayRenderer {
guard overlay is MKPolyline else {
return MKPolylineRenderer()
}
...
}
Good luck!