CLLocationManager只能運行一次

Question

我是新來的swift--目前，我的當前位置只在控制檯中輸出一次，當我通過override func awakeFromNib()在init初次調用setupLocationManager()時。當我想通過調用locationManager.startUpdatingLocation()來輸出我的新位置時，當我用方法updateLocation()單擊一個按鈕時，它會輸出一個錯誤。有任何解決這個問題的方法嗎？所有的幫助表示讚賞。

import Cocoa 
import CoreLocation 

class StatusMenuController: NSObject, CLLocationManagerDelegate { 

@IBOutlet weak var statusMenu: NSMenu! 
let statusItem = NSStatusBar.system().statusItem(withLength: NSVariableStatusItemLength) 
var locationManager:CLLocationManager! 
var currentLocation:CLLocation? 

@IBAction func quitClicked(_ sender: NSMenuItem) { 
    NSApplication.shared().terminate(self) 
} 

@IBAction func updateClicked(_ sender: NSMenuItem) { 
    updateLocation() 
} 

func updateLocation() { 
    locationManager.startUpdatingLocation() 
} 

override func awakeFromNib() { 
    statusItem.menu = statusMenu 
    let icon = NSImage(named: "statusIcon") 
    icon?.isTemplate = true 
    statusItem.image = icon 
    statusItem.menu = statusMenu 
    setupLocationManager() 
} 

func setupLocationManager(){ 
    locationManager = CLLocationManager() 
    locationManager?.delegate = self 
    //self.locationManager?.requestAlwaysAuthorization() 
    locationManager?.desiredAccuracy = kCLLocationAccuracyNearestTenMeters 
    locationManager?.startUpdatingLocation() 

} 

// Below method will provide you current location. 
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 

    if currentLocation == nil { 
     currentLocation = locations.last 
     locationManager?.stopMonitoringSignificantLocationChanges() 
     let locationValue:CLLocationCoordinate2D = manager.location!.coordinate 

     print(locationValue) 

     locationManager?.stopUpdatingLocation() 
    } 
} 

// Below Method will print error if not able to update location. 
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) { 
    print("Error") 
} 

} 

Answer 1

有一個在位置設置一次（if currentLocation == nil）之後中止對更新位置代碼的if條件。在重新啓動管理器之前，必須重置currentLocation至nil。

@IBAction func updateClicked(_ sender: NSMenuItem) { 
    currentLocation = nil 
    updateLocation() 
}