核心位置委托在闭包中的价值

Question

您好我已经在Swift 3中实现了核心位置管理器，我想构建一个方法，从其委托中捕获位置值并返回闭包中的值，但不能这样做。任何帮助将不胜感激。

我的代码：

import Foundation
import CoreLocation

class LocationManager : NSObject, CLLocationManagerDelegate{

var location: CLLocation?
var locationManager : CLLocationManager?
var currentLocation : CLLocationCoordinate2D?
var latitude : String?
var longitude : String?
var lat : Float?
var lon : Float?

//  var locationManagerCallback : (Float?,Float?,String?,String?) ->()


static let sharedInstance : LocationManager = {
    let instance = LocationManager()
    return instance
}()


// MARK: - CLLocation Fetch Methods

func fetchLocationWithCompletionHandler(completion : @escaping(Float?,Float?,String?,String?) -> ()) -> Void {

    if locationManager != nil {

        locationManager?.stopUpdatingLocation()
        locationManager?.delegate = nil
        locationManager = nil
    }
    locationManager = CLLocationManager()
    locationManager?.delegate = self
    locationManager?.distanceFilter = kCLLocationAccuracyNearestTenMeters
    locationManager?.desiredAccuracy = kCLLocationAccuracyBest

    let requestWhenInUseSelector = NSSelectorFromString("requestWhenInUseAuthorization")
    let requestAlwaysSelector    = NSSelectorFromString("requestAlwaysAuthorization")

    if (locationManager?.responds(to: requestWhenInUseSelector))! {

        locationManager?.requestWhenInUseAuthorization()

    }else if (locationManager?.responds(to: requestAlwaysSelector))!{

        locationManager?.requestAlwaysAuthorization()
    }
    locationManager?.startUpdatingLocation()


}

func requestWhenInUseAuthorization() -> Void {

    let status : CLAuthorizationStatus = CLLocationManager.authorizationStatus()
    if status == CLAuthorizationStatus.denied  || status == CLAuthorizationStatus.restricted {
        // TODO : Handle Denial Here
    }else if status == CLAuthorizationStatus.notDetermined{
        locationManager?.requestWhenInUseAuthorization()
    }
}
func requestAlwaysAuthorization() -> Void {

    let status : CLAuthorizationStatus = CLLocationManager.authorizationStatus()
    if status == CLAuthorizationStatus.denied || status == CLAuthorizationStatus.restricted {
        // TODO : Handle Denial Here
    }else if status == CLAuthorizationStatus.notDetermined{
        locationManager?.requestAlwaysAuthorization()
    }

}


func reveseGeocode(currentLocation : CLLocation, completionCallback : @escaping(CLPlacemark?,Error?) -> Swift.Void) -> Void {

    let reverseGeocoder : CLGeocoder = CLGeocoder()
    reverseGeocoder.reverseGeocodeLocation(currentLocation) { (placemarkArray, error) in

        let placemark : CLPlacemark = (placemarkArray?.first)!
        completionCallback(placemark,error)
    }
}


// MARK: - CLLocation Delegate Methods

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

    self.location = locations[0]
    currentLocation = self.location?.coordinate
    lat = Float((currentLocation?.latitude)!)
    lon = Float((currentLocation?.longitude)!)
    latitude = String(format: "%lf",lat!)
    longitude = String(format : "%lf",lon!)

    UserDefaults.standard.set(lat, forKey: CURR_LAT_VAL)
    UserDefaults.standard.set(lon, forKey: CURR_LON_VAL)
    UserDefaults.standard.set(latitude, forKey: CURR_LAT_STR)
    UserDefaults.standard.set(longitude, forKey: CURR_LON_STR)
    UserDefaults.standard.synchronize()

    print("\(lat)\(lon)\(latitude)\(longitude)")

   // locManager(lat,lon,latitude,longitude)

}

func locationManagerDidPauseLocationUpdates(_ manager: CLLocationManager) {
    print("location manager did pause")
}

func locationManagerDidResumeLocationUpdates(_ manager: CLLocationManager) {
    print("location manager did resume")
}

func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
    print("Location fetch failed with error : \(error.localizedDescription)")
}

func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
    print("Authorization Changed")
}

}

Answer 1

您需要在LocationManager类中保存块变量，如下所示：

1.在你的班级中添加变量：

var locationManagerCallback: ((Float?,Float?,String?,String?) -> ())?

2.在启动请求时保存完成块/关闭：

func fetchLocationWithCompletionHandler(completion: @escaping(Float?,Float?,String?,String?) -> ()) -> Void {
    locationManagerCallback = completion

    ...
} 

3.从委托方法调用闭包：

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    locationManagerCallback?(lat, lon, latitude, longitude)
}

以下是如何从其他类中使用它：

LocationManager.sharedInstance.fetchLocationWithCompletionHandler { (lat, long, latitude, longitude) in
    print("\(lat)\(long)\(latitude)\(longitude)")
}

希望能帮助到你。