如何将谷歌地图摄像头聚焦于用户'；使用swiftUI视图启动时的当前位置

我正在尝试制作一个使用谷歌地图的应用程序，并在应用程序打开时关注用户的位置

现在，我已经初始化了地图，按下谷歌地图固有的“myLocation”按钮后，我可以聚焦到用户的位置，但地图的摄像头会一直聚焦到指定的位置，而不是用户的位置

我通过以下两个教程了解了我现在的处境： - -

在搜索Google和此处之后，似乎我需要利用CLLocationManager（）获取用户的设备坐标，然后以某种方式使用它？我认为我关于CLLocationManager（）的代码可能放在错误的文件中或使用不正确，但我没有收到任何错误

我的代码是这样工作的：SceneDelegate.swift将我的LandmarkList.swift设置为rootViewController。然后LandmarkList调用GoogMapView.swift来显示Google地图的实例

SceneDelegate.swift：

我想我在这里使用locationManager可能是错误的

import UIKit
import SwiftUI
import GoogleMaps
import GooglePlaces
import CoreLocation



class SceneDelegate: UIResponder, UIWindowSceneDelegate, CLLocationManagerDelegate {


    var window: UIWindow?
    private let locationManager = CLLocationManager()


    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
        // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
        // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).

        // Use a UIHostingController as window root view controller
        if let windowScene = scene as? UIWindowScene {
            let window = UIWindow(windowScene: windowScene)
            window.rootViewController = UIHostingController(rootView: LandmarkList())
            self.window = window
            window.makeKeyAndVisible()
        }

        locationManager.requestAlwaysAuthorization()

        if CLLocationManager.locationServicesEnabled() {
            locationManager.delegate = self
            locationManager.desiredAccuracy = kCLLocationAccuracyBest
            locationManager.requestWhenInUseAuthorization()
        }

    }
}

LandmarkList.swift：

import SwiftUI

struct LandmarkList: View {

    @State private var searchText = ""
    @State private var locationText = ""


    var body: some View {


            ZStack(alignment: Alignment.top) {
                GoogMapView()
                    .frame(height: 750)


                SlideOverCard {
                    VStack(alignment: .leading) {
                        List(landmarkData) { landmark in
                            NavigationLink(destination: LandmarkDetail(landmark: landmark)) {
                                LandmarkRow(landmark: landmark)
                            }
                        }

                    }
                        .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity, alignment: Alignment.topLeading)
                    }
        }
    }
}

GoogMapView.swift：

注意：下面的打印语句仅返回“用户位置未知”

import SwiftUI
import UIKit
import GoogleMaps
import GooglePlaces
import CoreLocation


struct GoogMapView : UIViewRepresentable {

        let marker : GMSMarker = GMSMarker()

        //Creates a `UIView` instance to be presented.
        func makeUIView(context: Context) -> GMSMapView {
            // Create a GMSCameraPosition
            let camera = GMSCameraPosition.camera(withLatitude: 42.361145, longitude: -71.057083, zoom: 16.0)
            let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
            mapView.setMinZoom(14, maxZoom: 20)
            mapView.settings.compassButton = true
            mapView.isMyLocationEnabled = true
            mapView.settings.myLocationButton = true
            mapView.settings.scrollGestures = true
            mapView.settings.zoomGestures = true
            mapView.settings.rotateGestures = true
            mapView.settings.tiltGestures = true
            mapView.isIndoorEnabled = false

            if let mylocation = mapView.myLocation {
              print("User's location: \(mylocation)")
            } else {
              print("User's location is unknown")
            }

            return mapView
        }

//        Updates the presented `UIView` (and coordinator) to the latestconfiguration.
    func updateUIView(_ mapView: GMSMapView, context: Context) {
        // Creates a marker in the center of the map.
        marker.position = CLLocationCoordinate2D(latitude: 42.361145, longitude: -71.057083)
        marker.title = "Boston"
        marker.snippet = "USA"
        marker.map = mapView
    }
}

同样，我认为我在SceneDelegate.swift中关于locationManager的代码会使GoogleMaps摄像头的实例在启动时关注用户的位置，但事实并非如此

有人知道我做错了什么吗？

您可以通过“假装”您的视图是ViewController来实现这一点。尝试将

谷歌地图视图

设置为代理。然后将初始化代码放入

makeUIView

中，然后遵守协议：

struct GoogMapView : CLLocationManagerDelegate {

private let locationManager = CLLocationManager()

  func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {

    guard status == .authorizedWhenInUse else {
      return
    }

    locationManager.startUpdatingLocation()


    mapView.isMyLocationEnabled = true
    mapView.settings.myLocationButton = true
  }


  func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    guard let location = locations.first else {
      return
    }


    mapView.camera = GMSCameraPosition(target: location.coordinate, zoom: 15, bearing: 0, viewingAngle: 0)


    locationManager.stopUpdatingLocation()
  }
}

---

以上摘自。

使用此处的注释和其他有关StackOverflow的注释，我提出了以下解决方案：

//
//  GoogMapView.swift
//  Landmarks
//
//  Created by Zahr Lyttle on 10/14/19.
//  Copyright © 2019 Apple. All rights reserved.
//

import SwiftUI
import UIKit
import GoogleMaps
import GooglePlaces
import CoreLocation
import Foundation



struct GoogMapView: View {
    var body: some View {
        GoogMapControllerRepresentable()
    }
}


class GoogMapController: UIViewController, CLLocationManagerDelegate {
    var locationManager = CLLocationManager()
    var mapView: GMSMapView!
    let defaultLocation = CLLocation(latitude: 42.361145, longitude: -71.057083)
    var zoomLevel: Float = 15.0
    let marker : GMSMarker = GMSMarker()


    override func viewDidLoad() {
        super.viewDidLoad()

        locationManager = CLLocationManager()
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestAlwaysAuthorization()
        locationManager.distanceFilter = 50
        locationManager.startUpdatingLocation()
        locationManager.delegate = self

        let camera = GMSCameraPosition.camera(withLatitude: defaultLocation.coordinate.latitude, longitude: defaultLocation.coordinate.longitude, zoom: zoomLevel)
        mapView = GMSMapView.map(withFrame: view.bounds, camera: camera)
        mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        mapView.isMyLocationEnabled = true
        mapView.setMinZoom(14, maxZoom: 20)
        mapView.settings.compassButton = true
        mapView.isMyLocationEnabled = true
        mapView.settings.myLocationButton = true
        mapView.settings.scrollGestures = true
        mapView.settings.zoomGestures = true
        mapView.settings.rotateGestures = true
        mapView.settings.tiltGestures = true
        mapView.isIndoorEnabled = false

//        if let mylocation = mapView.myLocation {
//          print("User's location: \(mylocation)")
//        } else {
//          print("User's location is unknown")
//        }

        marker.position = CLLocationCoordinate2D(latitude: 42.361145, longitude: -71.057083)
        marker.title = "Boston"
        marker.snippet = "USA"
        marker.map = mapView

        // Add the map to the view, hide it until we've got a location update.
        view.addSubview(mapView)
//        mapView.isHidden = true

    }

    // Handle incoming location events.
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
      let location: CLLocation = locations.last!
      print("Location: \(location)")

      let camera = GMSCameraPosition.camera(withLatitude: location.coordinate.latitude, longitude: location.coordinate.longitude, zoom: zoomLevel)

      if mapView.isHidden {
        mapView.isHidden = false
        mapView.camera = camera
      } else {
        mapView.animate(to: camera)
      }

    }

    // Handle authorization for the location manager.
    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
      switch status {
      case .restricted:
        print("Location access was restricted.")
      case .denied:
        print("User denied access to location.")
        // Display the map using the default location.
        mapView.isHidden = false
      case .notDetermined:
        print("Location status not determined.")
      case .authorizedAlways: fallthrough
      case .authorizedWhenInUse:
        print("Location status is OK.")
      }
    }

    // Handle location manager errors.
    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
      locationManager.stopUpdatingLocation()
      print("Error: \(error)")
    }

}


struct GoogMapControllerRepresentable: UIViewControllerRepresentable {
    func makeUIViewController(context: UIViewControllerRepresentableContext<GMControllerRepresentable>) -> GMController {
        return GMController()
    }

    func updateUIViewController(_ uiViewController: GMController, context: UIViewControllerRepresentableContext<GMControllerRepresentable>) {

    }
}

//
//斯威夫特
//地标
//
//扎尔·利特尔于19年10月14日创作。
//版权所有©2019苹果公司。版权所有。
//
导入快捷键
导入UIKit
导入谷歌地图
导入谷歌网站
导入核心定位
进口基金会
结构GoogMapView：视图{
var body：一些观点{
GoogMapControllerRepresentable（）
}
}
类GoogMapController:UIViewController、CLLocationManagerDelegate{
var locationManager=CLLocationManager（）
var地图视图：GMSMapView！
设defaultLocation=CLLocation（纬度：42.361145，经度：-71.057083）
var zoomLevel:Float=15.0
let marker:GMSMarker=GMSMarker（）
重写func viewDidLoad（）{
super.viewDidLoad（）
locationManager=CLLocationManager（）
locationManager.desiredAccuracy=KCallocationAccuracyBest
locationManager.requestAlwaysAuthorization（）
locationManager.distanceFilter=50
locationManager.startUpdatingLocation（）
locationManager.delegate=self
让camera=GMSCameraPosition.camera（带纬度：defaultLocation.coordinate.latitude，经度：defaultLocation.coordinate.latitude，缩放：zoomLevel）
mapView=GMSMapView.map（带边框：view.bounds，相机：相机）
mapView.autoresizingMask=[.flexibleWidth、.flexibleHeight]
mapView.isMyLocationEnabled=true
mapView.setMinZoom（14，maxZoom:20）
mapView.settings.compassButton=true
mapView.isMyLocationEnabled=true
mapView.settings.myLocationButton=true
mapView.settings.ScrollPictures=true
mapView.settings.zoomGestures=true
mapView.settings.rotateGestures=true
mapView.settings.tiltsignities=true
mapView.ISINDORENABLED=false
//如果让mylocation=mapView.mylocation{
//打印（“用户位置：\（mylocation）”）
//}其他{
//打印（“用户位置未知”）
//        }
marker.position=CLLocationCoordinate2D（纬度：42.361145，经度：-71.057083）
marker.title=“波士顿”
marker.snippet=“美国”
marker.map=mapView
//将地图添加到视图中，隐藏它，直到获得位置更新。
view.addSubview（地图视图）
//mapView.ishiden=true
}
//处理传入的位置事件。
func locationManager（manager:CLLocationManager，didUpdateLocations位置：[CLLocation]）{
let location:CLLocation=locations.last！
打印（“位置：\（位置）”）
让camera=GMSCameraPosition.camera（带纬度：位置.坐标.纬度，经度：位置.坐标.经度，缩放：缩放级别）
如果mapView.isHidden{
mapView.ishiden=false
mapView.camera=camera
}否则{
地图视图.动画（到：摄影机）
}
}
//处理位置管理器的授权。
func locationManager（\ manager:CLLocationManager，didChangeAuthorization状态：CLAuthorizationStatus）{
开关状态{
案例.限制性：
打印（“位置访问被限制。”）
案件.驳回：
打印（“用户拒绝访问位置”）
//使用默认位置显示地图。
mapView.ishiden=false
案例。未确定：
打印（“位置状态未确定”）
案例.方法：失败
案例.授权使用：
打印（“位置状态正常”）
}
}
//处理位置管理器错误。
func locationManager（manager:CLLocationManager，didFailWithError:error）{
locationManager.StopUpdatengLocation（）
打印（“错误：\（错误）”）
}
}
结构GoogMapControllerRepresentable:UIViewControllerRepresentable{
func makeUIViewController（上下文：UIViewControllerRepresentableContext）->GMController{
返回GMController（）
}
func updateUIViewController（uViewController:GMController，上下文：UIViewControllerRepresentableContext）{
}
}

我终于能够想出如何立即关注“我的位置”，而不需要用户的输入。这里有更多的细节…希望对你有所帮助

updateUIView

• 你

  import SwiftUI
  import GoogleMaps
  import Combine
  
  struct HomeView: UIViewRepresentable {
  
      // Listen to changes on the locationManager
      @ObservedObject var locationManager = LocationManager()
  
      func makeUIView(context: Self.Context) -> GMSMapView {
  
          // Just default the camera to anywhere (this will be overwritten as soon as myLocation is grabbed
          let camera = GMSCameraPosition.camera(withLatitude: 0, longitude: 0, zoom: 16.0)
          let mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
          mapView.setMinZoom(14, maxZoom: 20)
          mapView.settings.compassButton = true
          mapView.isMyLocationEnabled = true
          mapView.settings.myLocationButton = true
          mapView.settings.scrollGestures = true
          mapView.settings.zoomGestures = true
          mapView.settings.rotateGestures = true
          mapView.settings.tiltGestures = true
          mapView.isIndoorEnabled = false
  
          return mapView
      }
  
      func updateUIView(_ mapView: GMSMapView, context: Self.Context) {
  
          // When the locationManager publishes updates, respond to them
          if let myLocation = locationManager.lastKnownLocation {
              mapView.animate(toLocation: myLocation.coordinate)
              print("User's location: \(myLocation)")
          }
      }
  }
  

  class LocationManager: NSObject, CLLocationManagerDelegate, ObservableObject {
  
      // Publish the user's location so subscribers can react to updates
      @Published var lastKnownLocation: CLLocation? = nil
      private let manager = CLLocationManager()
  
      override init() {
          super.init()
          self.manager.delegate = self
          self.manager.startUpdatingLocation()
      }
  
      func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
          if status == .authorizedWhenInUse {
              self.manager.startUpdatingLocation()
          }
      }
  
      func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
          // Notify listeners that the user has a new location
          self.lastKnownLocation = locations.last
      }
  }