location manager not updating in swift ios10 - ios

Question

I am new to swift and am trying to get a basic program that display the longitude and latitutde.
import UIKit
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
#IBOutlet weak var latLabel: UILabel!
#IBOutlet weak var longLabel: UILabel!
#IBOutlet weak var addLabel: UILabel!
var lm = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
lm = CLLocationManager()
}
#IBAction func getCurrentLocation(_ sender: AnyObject) {
lm.delegate = self
lm.desiredAccuracy = kCLLocationAccuracyBest
lm.startUpdatingLocation()
print("loc")
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print ("error")
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print ("location")
let length = locations.count
let curLoc = locations[length-0]
latLabel.text = String(curLoc.coordinate.latitude)
print ("loccation")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

Answer 1

You are missing two things.
you have to ask for permission using requestAlwaysAuthorization or requestWhenInUseAuthorization().
So when you are allocating your location manager in viewdidlod, Do like this
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
You need to add information as #Anbu.Karthik has suggested in his answer.
Use NSLocationAlwaysUsageDescription for apps that want to use the
device's location even when the app is not open and being used.
Use NSLocationWhenInUseUsageDescription for apps that want to use the
device's location only when the app is open and in use.

Answer 2

check once are you added the following information your plist
Location :
Key : Privacy - Location Always Usage Description
Value : $(PRODUCT_NAME) location use
Key : Privacy - Location When In Use Usage Description
Value : $(PRODUCT_NAME) location use
for more information see this

Answer 3

One other issue that I found caused the location update callback not to be called, with no obvious error message given is that it must not be a private function (which is obvious once you finally notice it, of course...). I realise the OP's one is not but this is a common place to end up if you are having issues, so it may help someone.
So the following will cause the function not to be called without giving any obvious error indication like crashing the app etc:
private func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print ("location")
let length = locations.count
let curLoc = locations[length-0]
latLabel.text = String(curLoc.coordinate.latitude)
print ("loccation")
}
Removing the 'private' keyword, as in the OP's code, will allow it to be called.