Swift 2使用CLLocation获得速度

Question

I try to make an application in Swift 2 that displays all the GPS informations. I can recover latitute, longitue, horizontalAccuracy, verticalAccuracy, altitude, distance and cap but I am unable to recover speed, whereas I arrived in Objective-C :-(

Thanks for your help

Below is my code:

import UIKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {

var running = false
var pause = false
var locationManager: CLLocationManager = CLLocationManager()
var startLocation: CLLocation!

@IBOutlet weak var latitudeLabel: UILabel!
@IBOutlet weak var longitudeLabel: UILabel!

@IBOutlet weak var horizontalAccuracyLabel: UILabel!
@IBOutlet weak var verticalAccuracyLabel: UILabel!

@IBOutlet weak var capLabel: UILabel!
@IBOutlet weak var altitudeLabel: UILabel!


@IBOutlet weak var partielLabel: UILabel!
@IBOutlet weak var distanceLabel: UILabel!

@IBOutlet weak var vitesseLabel: UILabel!
@IBOutlet weak var moyenneLabel: UILabel!
@IBOutlet weak var timerLabel: UILabel!
@IBOutlet weak var totalDistanceLabel: UILabel!


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

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

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func startDistance(sender: AnyObject) {
    startLocation = nil
    running = true
}

@IBAction func stopDistance(sender: AnyObject) {
    running = false
}

@IBAction func resetDistance(sender: AnyObject) {
    startLocation = nil
}


func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
    let latestLocation: AnyObject = locations[locations.count - 1]

    latitudeLabel.text = String(format: "%.4f",latestLocation.coordinate.latitude)
    longitudeLabel.text = String(format: "%.4f",latestLocation.coordinate.longitude)

    horizontalAccuracyLabel.text = String(format: "%.4f",latestLocation.horizontalAccuracy)
    verticalAccuracyLabel.text = String(format: "%.4f",latestLocation.verticalAccuracy)

    altitudeLabel.text = String(format: "%.4f",latestLocation.altitude)

    if running == true {
        if startLocation == nil {
            startLocation = latestLocation as! CLLocation
        }

        let distanceBetween: CLLocationDistance =
        latestLocation.distanceFromLocation(startLocation)

        distanceLabel.text = String(format: "%.2f", distanceBetween)
    }
}

func locationManager(manager: CLLocationManager, didUpdateHeading newHeading: CLHeading)
{
    capLabel.text = String(format: "%.4f",newHeading.magneticHeading)
}


func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {

}

}

I tested this code :

vitesseLabel.text = String(CLLocationSpeed())

but speed remains at 0.00

Answer 1

I finally found, so here's the code:

var speed: CLLocationSpeed = CLLocationSpeed()
speed = locationManager.location!.speed
vitesseLabel.text = String(format: "%.0f km/h", speed * 3.6)

Answer 2

您不知道速度的原因是，您没有在向CLLocation询问其speed地方编写任何代码。