IOS 使用CoreLocation定位 不弹出权限提示

代码如下：

    var locationManager:CLLocationManager!

override func viewDidLoad() {
    super.viewDidLoad()

    locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.distanceFilter = kCLDistanceFilterNone
    if #available(iOS 8.0, *) {
        locationManager.requestWhenInUseAuthorization()
    } else {
        // Fallback on earlier versions
    }
    locationManager.startUpdatingLocation()
}

解决：
1、引入 CoreLocation.framework

2、修改info.plist
NSLocationAlwaysUsageDescription
NSLocationWhenInUseUsageDescription

再次运行即可弹出定位提示