ios - 用户位置不会出现在 Xcode 的模拟器中

Question

我是应用程序开发的新手，我试图让用户位置出现在模拟器中，但我一直收到使用未解析的标识符错误。我查看了其他问题，这些问题非常针对他们自己的项目，并尝试以类似的方式处理我自己的应用程序但无济于事。有什么帮助吗？这是我的代码，以及指向 Xcode 屏幕截图的链接。

import UIKit
import MapKit
import CoreLocation

class SecondViewController: UIViewController, CLLocationManagerDelegate {

    //Map
    @IBOutlet weak var map: MKMapView!

    let manager = CLLocationManager()
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
    {   let location = locations[0]

        let span:MKCoordinateSpan = MKCoordinateSpanMake(0.01, 0.01)

        let myLocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)

        let region:MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span)


        self.map.showsUserLocation = true

    }

    override func viewDidLoad()
    {
        super.viewDidLoad()
        manager.delegate = self
        manager.desiredAccuracy = kCLLocationAccuracyBest
        manager.requestWhenInUseAuthorization()
        manager.startUpdatingLocation()

        //This is where I get an error
         map.setRegion(region, animated: true)**
    }

Error: Use of unresolved identifier

Answer 1

您的 let region:MKCoordinateRegion 是您的委托(delegate)方法中的本地标识符:

func locationManager(_:didUpdateLocations) {...}

这就是为什么您会使用未解析的标识符。让这个identifier在整个类中都可以访问，错误就会消失。喜欢:

class SecondViewController: UIViewController, CLLocationManagerDelegate {

    //Map
    @IBOutlet weak var map: MKMapView!
    var region = MKCoordinateRegion()
    .......
    .......
}

注意:但这不会让您在 map 上看到任何东西。从您的 MapView 查看任何输出的最佳方式是将 map.setRegion(region, animated: true) 放入您的 delegate 方法中:

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    let location = locations.first
    let span = MKCoordinateSpanMake(0.01, 0.01)
    let myLocation = CLLocationCoordinate2DMake((location?.coordinate.latitude)!, (location?.coordinate.longitude)!)
    region = MKCoordinateRegionMake(myLocation, span)
    map.setRegion(region, animated: true)
}