ios - 我在 Swift 10.2 上运行自编码应用程序时遇到问题

Question

Xcode 说有一个 Thread 1: signal SIGABRT 。它还说 libc++abi.dylib: 以 NSException 类型的未捕获异常终止(lldb)。我是初学者，所以请回复“轻松”;)

//  ViewController.swift

import UIKit
import MapKit
import CoreLocation

class MapScreen: UIViewController {

    @IBOutlet weak var mapView: MKMapView!

    let locationManager = CLLocationManager()


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

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


    func checkLocationServices() {
        if CLLocationManager.locationServicesEnabled() {
            setupLocationManager()
            checkLocationAuthorization()
        }else{
            // show alert letting the user know he has to turn them on.
        }
    }


    func checkLocationAuthorization() {
        switch CLLocationManager.authorizationStatus() {
        case .authorizedWhenInUse:
            mapView.showsUserLocation = true
            break
        case .denied:
            // show alert instructing how to turn on permissions
            break
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
        case .restricted:
            // show an alert letting them know what's up
            break
        case .authorizedAlways:
            break
        }
    }
}


    extension MapScreen: CLLocationManagerDelegate {
        func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
            // later
            }
        func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
            // later
        }
    }

Answer 1

要填充圆圈(在将 UI 控件连接到 Storyboard的 @IBOutlet 旁边)，您需要打开 .swift文件和 Storyboard，尝试这些以确保其实际连接

• 打开 Storyboard文件，然后打开 MapScreen.swift文件中，如果已连接，则应填充连接器
• 打开 Storyboard 文件并单击以显示 Assistant Editor所以 Storyboard和 MapScreen.swift文件是并行打开的，还要确保将 Class 设置为 MapScreen在Identity Inspector ，如下面的屏幕截图所示

我还将列出一些有关 MKMapView 和 LocationManager 的建议

---

• locationManager.requestWhenInUseAuthorization()将不起作用，如果 Info.plist没有以下一项或多项使用说明

  <key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
  <string>Message for AlwaysAndWhenInUseUsageDescription</string>
  
  <key>NSLocationAlwaysUsageDescription</key>
  <string>Message for AlwaysUsageDescription</string>
  
  <key>NSLocationWhenInUseUsageDescription</key>
  <string>Message for WhenInUseUsageDescription</string>
  

• 一旦获得使用定位服务的权限，需要询问locationManager.startUpdatingLocation()因此您将通过 CLLocationManagerDelegate 获得位置更新

• 在locationManager(_:didUpdateLocations:)内收到位置更新，为了能够在 map 上查看用户位置，我们需要将 map 区域设置为该位置，使用 mapView.setRegion

---

这是更新后的类

class MapScreen: UIViewController {

    @IBOutlet var mapView: MKMapView!
    let locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        setupLocationManager()
    }

    func setupLocationManager() {
        guard CLLocationManager.locationServicesEnabled() else {
            // show alert letting the user know he has to turn them on.
            print("Location Servies: Disabled")
            return
        }

        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest

        checkLocationAuthorization()
    }

    func checkLocationAuthorization(authorizationStatus: CLAuthorizationStatus? = nil) {
        switch (authorizationStatus ?? CLLocationManager.authorizationStatus()) {
        case .authorizedAlways, .authorizedWhenInUse:
            locationManager.startUpdatingLocation()
            mapView.showsUserLocation = true
        case .restricted, .denied:
            // show alert instructing how to turn on permissions
            print("Location Servies: Denied / Restricted")
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
        }
    }
}


extension MapScreen: CLLocationManagerDelegate {

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.count > 1 ? locations.sorted(by: { $0.timestamp < $1.timestamp }).last : locations.first else { return }

        let span = MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)
        let region = MKCoordinateRegion(center: location.coordinate, span: span)
        mapView.setRegion(region, animated: true)
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        self.checkLocationAuthorization(authorizationStatus: status)
    }

}

结果