requestWhenInUseAuthorization()在iOS 8中不起作用Info.plist中的NSLocationWhenInUseUsageDescription键

Question

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程序的访问权限.我导入了CoreLocation.framework,并将NSLocationWhenInUseUsageDescription和NSLocationAlwaysUsageDescription键添加到info.plist中.当我运行应用程序时,它从未提示我进行位置访问.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"未确定"一次,没有别的.所以我去了iPhone模拟器=>设置=>隐私=>位置=>我的应用程序.它向我展示了3个选项:"从不","使用应用程序时","始终".但没有选择任何东西.

Answer 1

问题解决了.我manager被声明为局部var inside viewDidLoad()方法,但它应该是类级属性.

我将manager声明移出后viewDidLoad(),我的应用程序工作了.

不知道究竟是如何manager.requestWhenInUseAuthorization()在幕后工作,到底为什么manager中定义viewDidLoad()不起作用.希望知道这个细节的人启发我.