我在 Swift 10.2 上运行我的自编码应用程序时遇到问题答案

【问题标题】：I have a problem on running my self coded app on Swift 10.2我在 Swift 10.2 上运行我的自编码应用程序时遇到问题
【发布时间】：2019-08-23 03:33:21
【问题描述】：

Xcode 说有一个 Thread 1: signal SIGABRT 。它还说 libc++abi.dylib: terminating with uncaught exception of type NSException (lldb) 。我是初学者，所以请“轻松”回复；）

//  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
        }
    }

【问题讨论】：

您是否连接了情节提要中的mapView 插座？（你在 Xcode 中看到属性旁边的实心圆圈了吗？）。你看到位置权限提示了吗？您是否已将位置使用说明添加到您的info.plist？应该有与控制台中显示的异常相关的错误消息
@Paulw11 是的，除了实心圆圈外，一切似乎都很好。它没有被填满。但是我连接了它...
您收到错误消息，因为您告诉应用程序在地图上显示用户的当前位置。但该应用尚未准备好这样做，因为您不允许该应用访问地图视图的委托属性。
@ElTomato 我该如何解决这个问题？
搜索 showUserLocation 并阅读其他主题。

标签： ios swift mapkit sigabrt

【解决方案1】：

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

打开storyboard文件，再打开MapScreen.swift文件，连接器如果有连接就填上
打开故事板文件并单击以显示Assistant Editor，因此故事板和MapScreen.swift 文件同时打开，同时确保在Identity Inspector 中将Class 设置为MapScreen，如下面的屏幕截图所示

我也会列出一些关于 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>

一旦获得使用位置服务的权限，需要询问locationManager.startUpdatingLocation()，这样您将通过CLLocationManagerDelegate获得位置更新
在locationManager(_:didUpdateLocations:) 内接收位置更新，为了能够在地图上看到用户位置，我们需要将地图区域设置为该位置，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

【讨论】：