核心位置委托闭包中的值

Question

嗨，我已经在 Swift 3 中实现了核心位置管理器，我想构造一种方法，该方法将从其委托中捕获位置值并将闭包中的值返回给我，但无法这样做。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

您需要将

块变量保存在LocationManager类中，如下所示：

1. 在类中添加变量：

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

2. 保存启动请求时的完成块/闭包：

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)
}

以下是从其他类中使用它的方法：

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

希望对您有所帮助。