我正在使用iOS SDK
8.1尝试调用requestWhenInUseAuthorization（）方法来提示用户授予对我的应用的访问权限。我导入了CoreLocation.framework，并将NSLocationWhenInUseUsageDescription和NSLocationAlwaysUsageDescription键添加到info.plist中。当我运行该应用程序时，它从未提示我访问位置。以下是我的代码，我错过了什么？

import UIKit
import CoreLocation
import MapKit

class ViewController: UIViewController, CLLocationManagerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        var manager = CLLocationManager()
        manager.delegate = self
        manager.desiredAccuracy = kCLLocationAccuracyBest

        let authorizationStatus = CLLocationManager.authorizationStatus()
        switch authorizationStatus {
        case .Authorized:
            println("authorized")
        case .AuthorizedWhenInUse:
            println("authorized when in use")
        case .Denied:
            println("denied")
        case .NotDetermined:
            println("not determined")
        case .Restricted:
            println("restricted")
        }

        manager.requestWhenInUseAuthorization()
        manager.startUpdatingLocation()

    }

    func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        let location = locations[0] as CLLocation
        println("Latitude: \(location.coordinate.latitude). Longitude: \(location.coordinate.longitude).")
    }

    func locationManager(manager: CLLocationManager!, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
        switch status {
        case .Authorized:
            println("authorized")
        case .AuthorizedWhenInUse:
            println("authorized when in use")
        case .Denied:
            println("denied")
        case .NotDetermined:
            println("not determined")
        case .Restricted:
            println("restricted")
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

}

控制台只显示一次“不确定”，没有其他显示。所以我去了iPhone Simulator
=>设置=>隐私=>位置=>我的应用。它向我显示了3个选项：“从不”，“在使用应用程序时”，“始终”。但是什么也没选择。