fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

Question

I'm trying to add marker in google maps with long touch in swift !!!!! and when i add below code some errors raised !

class ViewController: UIViewController, CLLocationManagerDelegate, UIGestureRecognizerDelegate {

    var mapView: GMSMapView?
    var locationManager = CLLocationManager()
    var locationMarker: GMSMarker!

    override func viewDidLoad() {
        super.viewDidLoad()

        let longPressRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(ViewController.handleLongPress(_:)))
        self.mapView!.addGestureRecognizer(longPressRecognizer)

        GMSServices.provideAPIKey("AIzaSyBw95wEhcSiSBmPWuYkiK0_IBnZQK-Lm7I")


        locationManager.delegate = self
        locationManager.requestWhenInUseAuthorization()
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.startUpdatingLocation()
    }

    func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
        print("Error" + error.description)
    }

    func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        let userLocation = locations.last
        let center = CLLocationCoordinate2D(latitude: userLocation!.coordinate.latitude, longitude: userLocation!.coordinate.longitude)

        let camera = GMSCameraPosition.cameraWithLatitude(userLocation!.coordinate.latitude,
                                                          longitude: userLocation!.coordinate.longitude, zoom: 16)
        let mapView = GMSMapView.mapWithFrame(CGRectZero, camera: camera)
        mapView.myLocationEnabled = true
        mapView.settings.myLocationButton = true
        view = mapView

 // marker with optional position
       let  position = CLLocationCoordinate2DMake(10, 10)
        let marker = GMSMarker(position: position)


        marker.opacity = 0.6
        marker.position = center
        marker.title = "Current Location"
        marker.snippet = ""
        marker.map = mapView
        //mapView.clear()
        //locationManager.stopUpdatingLocation()

        }
    func handleLongPress(recognizer: UILongPressGestureRecognizer)
    {
        if (recognizer.state == UIGestureRecognizerState.Began)
        {
            let longPressPoint = recognizer.locationInView(self.mapView);
            let coordinate = mapView!.projection.coordinateForPoint(longPressPoint )
            //Now you have Coordinate of map add marker on that location

        }}


    }

You can see error page here !!!!

you can add breakpoints at viewDidLoad & didUpdateLocations to know exactly where the nil optional exists — Mohamed Mostafa, Jun 11 '16 at 10:20
Check if in didUpdateLocations delegate method, userlocation is nil or not — Ashish Verma, Jun 11 '16 at 10:28
You are wrapping mapView and adding UILongPressGestureRecognizer on it. And you are initializing mapView in didUpdateLocations . That's your problem by which you are getting error. Use this code: self.view.addGestureRecognizer(longPressRecognizer) — Ashish Verma, Jun 11 '16 at 10:37

score 1 · Answer 1 · answered Jun 11 '16 at 10:24

1

Error is raised in didUpdateLocations methods because its seems that sometimes we are not getting location so its passing nil on there.

So you can used try catch block or either use If let syntax to avoid this problem.

answered Jun 11 '16 at 10:24

Lotus Shah

493
4
13

didUpdateLocations don't get called unless it have locations and it can never be nil – Mohamed Mostafa Jun 11 '16 at 10:30

score 0 · Accepted Answer · answered Jun 11 '16 at 10:32

0

The problem is that you use map view without it is being initialized

var mapView: GMSMapView?

in viewDidLoad

    self.mapView!.addGestureRecognizer(longPressRecognizer)

answered Jun 11 '16 at 10:32

Mohamed Mostafa

1,057
7
12

what should i change ?! – P.Tb Jun 11 '16 at 10:34
self.view.addGestureRecognizer(longPressRecognizer) – Mohamed Mostafa Jun 11 '16 at 10:36
var position = coordinate var marker = GMSMarker(position: position) marker.title = "Test Marker" marker.map = mapView – Mohamed Mostafa Jun 11 '16 at 10:45
please mark this answer as true & try this :: var tempMapSubView = self.views[0] as! GMSMapView marker.map = tempMapSubView – Mohamed Mostafa Jun 11 '16 at 10:59
Value of type 'ViewController' has no member 'views' – P.Tb Jun 11 '16 at 11:03
check this http://stackoverflow.com/questions/36859024/gmsmarker-not-appearing-on-map && http://iosallinone.blogspot.com.eg/2015/04/a-swift-tutorial-for-google-maps-sdk.html – Mohamed Mostafa Jun 11 '16 at 11:09

fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

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