ios - 总是调用 Swift LocationManager didChangeAuthorizationStatus

Question

我有一个 View Controller ，它实现了 CLLocationManagerDelegate。我创建了一个 CLLocationManager 变量:

let locationManager = CLLocationManager()

然后在 viewDidLoad 中，我设置属性:

// Set location manager properties
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters
locationManager.distanceFilter = 50

问题是在我检查授权状态之前就调用了该函数。

func locationManager(manager: CLLocationManager!, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
    if (status == .AuthorizedWhenInUse) {
        // User has granted autorization to location, get location
        locationManager.startUpdatingLocation()
    }
}

谁能告诉我是什么导致了这种情况的发生？

Answer 1

- locationManager:didChangeAuthorizationStatus: 在 CLLocationManager 初始化后不久被调用。

如果需要，您可以在委托(delegate)方法中请求授权:

func locationManager(manager: CLLocationManager!, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
    switch status {
    case .notDetermined:
        locationManager.requestAlwaysAuthorization()
        break
    case .authorizedWhenInUse:
        locationManager.startUpdatingLocation()
        break
    case .authorizedAlways:
        locationManager.startUpdatingLocation()
        break
    case .restricted:
        // restricted by e.g. parental controls. User can't enable Location Services
        break
    case .denied:
        // user denied your app access to Location Services, but can grant access from Settings.app
        break
    default:
        break
    }
}

请注意，如果您希望它起作用，您需要在“及时”的事务中分配委托(delegate)。

如果你想以某种方式延迟委托(delegate)分配，例如通过异步设置，您可能会错过对 - locationManager:didChangeAuthorizationStatus: 的初始调用。