我正在为iOS 8开发一个Swift代码。我正在尝试做一些涉及位置的事情，因此我在swift视图控制器文件中实现了以下内容：

let locationManger:CLLocationManager = CLLocationManager()

var speedReceived:Double = 0

override func viewDidLoad() {
    super.viewDidLoad()
    locationManger.delegate = self
    locationManger.desiredAccuracy = kCLLocationAccuracyBest
    let authstate = CLLocationManager.authorizationStatus()
    if(authstate == CLAuthorizationStatus.NotDetermined){
       println("Not Authorised")  
      locationManger.requestWhenInUseAuthorization()
    }
    // Do any additional setup after loading the view, typically from a nib.
}

func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!){
    var location:CLLocation = locations[locations.count - 1] as CLLocation
    if(location.horizontalAccuracy > 0){
        self.speedReceived = location.speed
        println(self.speedReceived)
    }
}

func locationManager(manager: CLLocationManager!, didFailWithError error: NSError!) {
   println("Couldn't get your location")
}

但是，我似乎无法使此代码正常工作。它不会保存我对位置使用的偏好。它甚至不提示我允许访问位置。我尝试更新我的info.plist。但这不起作用。顺便说一句，如果我始终在模拟器的隐私设置中选择，那么如果我立即切换回该应用程序，它将起作用。有人可以帮忙吗？我确定那是问题所在，因为我在控制台上获得了未授权。

有什么帮助吗？