Measure distance in real time with CoreLocation in Swift

Question

I'm making an app that measure's speed and distance in real time. so I'm having problem with measuring distance. I tried to figure out something by getting location variable outside of function by return. But if I do this, speed measurement doesn't work. So how can I start measuring distance when "start" tapped then stop when "stop" button tapped?

@IBAction func startStopButtonDidTouch(_ sender: UIButton) {
    if isStarted { //When tapped STOP
        timer?.invalidate()
        isStarted = false
        locationManager.stopUpdatingLocation()
        startStopButton.setTitle("START", for: .normal)
   
    } else { //When tapped START
        locationManager.startUpdatingLocation()
        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateTimeLabel), userInfo: nil, repeats: true)
        isStarted = true
        startStopButton.setTitle("STOP", for: .normal)
    }
}

func locationManager (_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let location = locations[0]
    speedLabel.text = "\(Int(location.speed * 3.6))" 
}

Answer 1

Starting the location updates you will get updates in the didUpdateLocations method.

This method will work fine to start the location updates and to stop it.

var startLocation:CLLocation!
@IBAction func startStopButtonDidTouch(_ sender: UIButton) {
    if isStarted { //When tapped STOP
        timer?.invalidate()
        isStarted = false
        locationManager.stopUpdatingLocation()
        startStopButton.setTitle("START", for: .normal)
   
  } else { //When tapped START
    locationManager.startUpdatingLocation()
    isStarted = true
    startStopButton.setTitle("STOP", for: .normal)
   }
}

Here you have to update your labels with distance and speed in real-time.

func locationManager (_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) 
{
            let location = locations[0]
            speedLabel.text = "\(Int(location.speed * 3.6))"
   if (startLocation == nil)
   {
      startLocation = location;
   }
   let endLocation = location;
            //Distance measure code will be placed here.
   //In KM
   let distance = startLocation.distance(from: endLocation) / 1000
}