我目前正在尝试显示一个使用SwiftUI在启动时重点关注用户位置的Google Maps实例。
要显示地图，我在主视图文件中调用GoogMapView（）视图。它只是将相机设置为聚焦在波士顿，并在启动时在波士顿放置一个标记。
此处为GoogMapView.swift的代码：
import SwiftUI
//import MapKit
import UIKit
import GoogleMaps
import GooglePlaces
import CoreLocation
import Foundation
struct GoogMapView : UIViewRepresentable {
// private let locationManager = CLLocationManager()
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")
}
// locationManager.desiredAccuracy = kCLLocationAccuracyBest
// locationManager.requestAlwaysAuthorization()
// locationManager.distanceFilter = 50
// locationManager.startUpdatingLocation()
// locationManager.delegate = self
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
}
}
上面我注释掉的代码是我试图让GMSMapView相机在启动时专注于用户设备的位置（如google开发人员页面上所述），但我一直收到错误消息：“无法将类型'GoogMapView'的值分配给类型'CLLocationManagerDelegate ？在与“ locationManager.delegate = self”的行上]
我已经阅读过我需要利用'UIViewControllerRepresentable'包装以上代码来解决此问题。这是一个包裹有人为我提供参考的示例：
struct PageViewController: UIViewControllerRepresentable {
var controllers: [UIViewController]
@Binding var currentPage: Int
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> UIPageViewController {
let pageViewController = UIPageViewController(
transitionStyle: .scroll,
navigationOrientation: .horizontal)
pageViewController.dataSource = context.coordinator
pageViewController.delegate = context.coordinator
return pageViewController
}
func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
pageViewController.setViewControllers(
[controllers[currentPage]], direction: .forward, animated: true)
}
class Coordinator: NSObject, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var parent: PageViewController
init(_ pageViewController: PageViewController) {
self.parent = pageViewController
}
func pageViewController(
_ pageViewController: UIPageViewController,
viewControllerBefore viewController: UIViewController) -> UIViewController?
{
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index == 0 {
return parent.controllers.last
}
return parent.controllers[index - 1]
}
func pageViewController(
_ pageViewController: UIPageViewController,
viewControllerAfter viewController: UIViewController) -> UIViewController?
{
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index + 1 == parent.controllers.count {
return parent.controllers.first
}
return parent.controllers[index + 1]
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed,
let visibleViewController = pageViewController.viewControllers?.first,
let index = parent.controllers.firstIndex(of: visibleViewController)
{
parent.currentPage = index
}
}
}
}
有人知道我如何在启动时通过将其包装在'UIViewController'中来获取GoogMapView.swift中的地图以将用户的位置居中？
适合需要此功能的人：
//
// 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>) {
}
}