SWIFT - LocationManager循环多次？

我首先建议一些事情:

stopUpdatingLocation在表演之前打电话reverseGeocodeLocation.

您正在完成处理程序关闭stopUpdatingLocation内部调用reverseGeocodeLocation.问题在于它以异步方式运行,因此didUpdateLocations可能在中间期间接收额外的位置更新.通常,当您第一次启动位置服务时,您将获得许多更新,通常会提高准确性(例如,horizontalAccuracy值越来越小).如果在启动异步地理编码请求之前关闭位置服务,则可以最大限度地减少此问题.

您还可以添加添加distanceFilter中viewDidLoad,将尽量减少对委托方法重复的调用:

locationManager.distanceFilter = 1000

您可以使用自己的状态变量来检查是否已启动反向地理编码过程.例如:

private var didPerformGeocode = false

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    // if we don't have a valid location, exit

    guard let location = locations.first where location.horizontalAccuracy >= 0 else { return }

    // or if we have already searched, return

    guard !didPerformGeocode else { return }

    // otherwise, update state variable, stop location services and start geocode

    didPerformGeocode = true
    locationManager.stopUpdatingLocation()

    CLGeocoder().reverseGeocodeLocation(location) { placemarks, error in
        let placemark = placemarks?.first

        // if there's an error or no placemark, then exit

        guard error == nil && placemark != nil else {
            print(error)
            return
        }

        let city = placemark?.locality ?? ""
        let state = placemark?.administrativeArea ?? ""

        self.navigationBar.title = ("\(city), \(state)")
        self.usersLocation = ("\(city), \(state)")
        print(self.usersLocation)
        self.refreshPosts()
    }
}