MapKit zoom to user current location

Question

I am trying to simply show user's location on the map, but I need to when app launches, the map should zoom to current location ,but I don't know why map doesn't zoom at all and it's like this :

Here is the code :

class MapViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!
    var locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        mapView.delegate = self
        mapView.showsUserLocation = true
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestWhenInUseAuthorization()
        locationManager.delegate = self
        DispatchQueue.main.async {
            self.locationManager.startUpdatingLocation()
        }
    }

    func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        let location = locations.last as! CLLocation
        let center = CLLocationCoordinate2D(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude)
        var region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))
        region.center = mapView.userLocation.coordinate
        mapView.setRegion(region, animated: true)
    }

Answer 1

I faced similar issue and wasted 4 days thinking whats going wrong. Finally resolved with creating these lines of code in viewDidLoad Method :

    //Zoom to user location
    let noLocation = CLLocationCoordinate2D()
    let viewRegion = MKCoordinateRegionMakeWithDistance(noLocation, 200, 200)
    mapView.setRegion(viewRegion, animated: false)
    mapView.showsUserLocation = true

In ViewDidLoad Method add these new changes code :

override func viewDidLoad() {

    super.viewDidLoad()

    let locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest

    // Check for Location Services
    if (CLLocationManager.locationServicesEnabled()) {
        locationManager.requestAlwaysAuthorization()
        locationManager.requestWhenInUseAuthorization()
    }

    //Zoom to user location
    if let userLocation = locationManager.location?.coordinate {
        let viewRegion = MKCoordinateRegionMakeWithDistance(userLocation, 200, 200)
        mapView.setRegion(viewRegion, animated: false)
    }

    self.locationManager = locationManager

    DispatchQueue.main.async {
        self.locationManager.startUpdatingLocation()
    }

}

Hope this helps to resolve your issue. Feel free to post comment if any further issue. Thanks