在地图SwiftUI上显示用户位置 [英] Show user location on map SwiftUI

问题描述

我正在尝试加载地图，并在用户的位置上显示初始位置，并使用SwiftUI在地图上显示用户的位置.我不知道如何在SwiftUI中做到这一点.

I am trying to load a map and have the initial location on user's location as well as showing the user's location on the map using SwiftUI. I don't know how to do that in SwiftUI.

我试图将'view.showsUserLocation = true'放在updateUIView函数中，但是它不起作用.

I have tried to put 'view.showsUserLocation = true' in updateUIView function but it is not working.

import SwiftUI
import MapKit
struct MapView : UIViewRepresentable {
    func makeUIView(context: Context) -> MKMapView {
        MKMapView(frame: .zero)
    }

    func updateUIView(_ view: MKMapView, context: Context) {
        view.showsUserLocation = true
        let coordinate = CLLocationCoordinate2D(
            latitude: 34.011286, longitude: -116.166868)
        let span = MKCoordinateSpan(latitudeDelta: 2.0, longitudeDelta: 2.0)

        let region = MKCoordinateRegion(center: view.userLocation.location?.coordinate ?? coordinate, span: span)
        view.setRegion(region, animated: true)
    }
}

当我尝试打印该位置时，该位置为零.

The location comes nil when I tried to print it.

推荐答案

在Info.plist

然后尝试更新以下功能:

Then try with updating below function:

func updateUIView(_ view: MKMapView, context: Context) {

    view.showsUserLocation = true

    // Ask for Authorisation from the User.
    self.locationManager.requestAlwaysAuthorization()

    // For use in foreground
    self.locationManager.requestWhenInUseAuthorization()

    if CLLocationManager.locationServicesEnabled() {
        //        self.locationManager.delegate = self
         self.locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
         self.locationManager.startUpdatingLocation()

        //Temporary fix: App crashes as it may execute before getting users current location
        //Try to run on device without DispatchQueue

        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
            let locValue:CLLocationCoordinate2D = self.locationManager.location!.coordinate
            print("CURRENT LOCATION = \(locValue.latitude) \(locValue.longitude)")

            let coordinate = CLLocationCoordinate2D(
                latitude: locValue.latitude, longitude: locValue.longitude)
            let span = MKCoordinateSpan(latitudeDelta: 2.0, longitudeDelta: 2.0)
            let region = MKCoordinateRegion(center: coordinate, span: span)
            view.setRegion(region, animated: true)

        })
    }

}

这篇关于在地图SwiftUI上显示用户位置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！