Swift 地图：在隐式展开可选值时意外发现 nil

Question

我正在使用位置显示功能

当运行我的应用程序显示此消息时->

Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value: file

这是我的代码

import UIKit
import MapKit
import CoreLocation
class ViewController: UIViewController,CLLocationManagerDelegate {
    @IBOutlet weak var mymap: MKMapView!
    var locationManager: CLLocationManager!

    override func viewDidLoad() {
          checkLocationSevices()
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    func setupLocationManger()
    {
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
    }

    func checkLocationSevices()
    {
        if CLLocationManager.locationServicesEnabled()
        {
            setupLocationManger()
            checkLocationAuthorizatiob()
        }
        else
        {

        }
    }
    func checkLocationAuthorizatiob()
    {
        switch CLLocationManager.authorizationStatus()
        {
        case .authorizedWhenInUse:
            mymap.showsUserLocation = true
            break
        case .denied:
            break
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
            break
        case .restricted:
            break
        case .authorizedAlways:
            break

         default:
            break
        }
    }
}

我也加了ti info.plist -> 这是我得到的错误图像

Answer 1

这里有问题 ->

locationManager = CLLocationManager()

因为它就是这样做的 -> var locationManager: CLLocationManager!

所以 locationManager 的值将是 will 但是当添加 -> locationManager = CLLocationManager() -> 你将得到 locationManager

的值

import UIKit
import MapKit
import CoreLocation
class ViewController: UIViewController,CLLocationManagerDelegate {
    @IBOutlet weak var mymap: MKMapView!
    var locationManager: CLLocationManager!

    override func viewDidLoad() {
      locationManager = CLLocationManager()
          checkLocationSevices()
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    func setupLocationManger()
    {
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
    }

    func checkLocationSevices()
    {
        if CLLocationManager.locationServicesEnabled()
        {
            setupLocationManger()
            checkLocationAuthorizatiob()
        }
        else
        {

        }
    }
    func checkLocationAuthorizatiob()
    {
        switch CLLocationManager.authorizationStatus()
        {
        case .authorizedWhenInUse:
            mymap.showsUserLocation = true
            break
        case .denied:
            break
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
            break
        case .restricted:
            break
        case .authorizedAlways:
            break

         default:
            break
        }
    }
}

Swift 地图：在隐式展开可选值时意外发现 nil

Swift Maps: Unexpectedly found nil while implicitly unwrapping an Optional value

ios

swift

xcode

mapkit

allocation