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Question

Sherstyuk

Asked:2022-03-18 16:23:41 +0000 UTC2022-03-18 16:23:41 +0000 UTC 2022-03-18 16:23:41 +0000 UTC

SwiftUI：如何获取 MapView 中心坐标并将它们输出到文本？

772

地图中心有一个红色十字准线，我需要获取这个十字准线所在的坐标，并在 Text 中显示出来。

有猜测是这样的

func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
            
            let currentLocation = mapView.centerCoordinate
                    print("👉 Координаты \(currentLocation)")

}

项目链接

2 个回答

Voted

VAndrJ · Answer 1 · 2022-03-19T15:37:39Z

Best Answer

VAndrJ

2022-03-19T15:37:39Z2022-03-19T15:37:39Z

您只需要将坐标“扔”到可以绘制它们的位置。根据该项目，这MapViewModel

我不会深入研究其中发生的事情，例如它已添加@Published，并且已经适应您的需求：

class MapViewModel: NSObject, ObservableObject, CLLocationManagerDelegate {
    @Published var center: CLLocationCoordinate2D?
...
// В координаторе добавлен @Binding
class Coordinator: NSObject, MKMapViewDelegate {
    @Binding var center: CLLocationCoordinate2D?

    init(center: Binding<CLLocationCoordinate2D?>) {
        self._center = center
    }
...
// Естественно его нужно передать:
func makeCoordinator() -> Coordinator {
    return MapView.Coordinator(center: $mapData.center)
}
...
// И использовать:
if let center = mapData.center {
    Text("Мои координаты: В: \(center.latitude) L: \(center.longitude)")
}

结果：

1

Sherstyuk · Answer 2 · 2022-03-20T17:30:56Z

我将发布项目的完整代码，也许有人会派上用场

主页.swift

import SwiftUI
import CoreLocation
import MapKit

struct Home: View {
    
    @StateObject var mapData = MapViewModel()
    // Location Manager....
    @State var locationManager = CLLocationManager()

    
    // Целик
    struct Cross: Shape {
        func path(in rect: CGRect) -> Path {
            return Path { path in
                path.move(to: CGPoint(x: rect.midX, y: 0))
                path.addLine(to: CGPoint(x: rect.midX, y: rect.maxY))
                path.move(to: CGPoint(x: 0, y: rect.midY))
                path.addLine(to: CGPoint(x: rect.maxX, y: rect.midY))
                path.move(to: CGPoint(x: rect.midX, y: rect.midY))
                path.addArc(center: CGPoint(x: rect.midX, y: rect.midY), radius: 10, startAngle: Angle(degrees: 0), endAngle: Angle(degrees: 360), clockwise: false)
            }
        }
    }
    
    var body: some View {
        
        ZStack {
            // Карта
            MapView()
                .environmentObject(mapData)
                .ignoresSafeArea(.all, edges: .all)
            
            // Целик
            Cross().stroke(Color.red)
                           .frame(width: 90, height: 90)
            
            // Всё что по верх карты
            VStack {
                VStack(spacing: 0) {
                    // Панель поиска
                    HStack {
                        Image(systemName: "magnifyingglass")
                            .foregroundColor(.gray)
                        TextField("Search", text: $mapData.searchTxt)
                            .colorScheme(.light)
                    }
                    .padding(.vertical,10)
                    .padding(.horizontal)
                    .background(Color.white)
                    // Displaying Results...
                    if !mapData.places.isEmpty && mapData.searchTxt != "" {
                        ScrollView {
                            VStack(spacing: 15) {
                                ForEach(mapData.places) {place in
                                    Text(place.placemark.name ?? "")
                                        .foregroundColor(.black)
                                        .frame(maxWidth: .infinity,alignment: .leading)
                                        .padding(.leading)
                                        .onTapGesture{
                                            mapData.selectPlace(place: place)
                                        }
                                    Divider()
                                }
                            }
                            .padding(.top)
                        }
                        .background(Color.white)
                    }
                    
                } .padding()
                Spacer()
                // Панель кнопок
                VStack {
                    Button(action: mapData.focusLocation, label: {
                        Image(systemName: "location.fill")
                            .font(.title2)
                            .padding(10)
                            .background(Color.primary)
                            .clipShape(Circle())
                    })
                    Button(action: mapData.updateMapType, label: {
                        Image(systemName: mapData.mapType == .standard ? "network" : "map")
                            .font(.title2)
                            .padding(10)
                            .background(Color.primary)
                            .clipShape(Circle())
                    })
                    if let center = mapData.center {
                        Text ("Мои координаты: В: \(center.latitude) L: \(center.longitude)")
                    }
                }
                .frame(maxWidth: .infinity, alignment: .trailing)
                .padding()
                
            }
            
        }
        .onAppear(perform: {
            // Setting Delegate...
            locationManager.delegate = mapData
            locationManager.requestWhenInUseAuthorization()
        })
        // Permission Denied Alert...
        .alert(isPresented: $mapData.permissionDenied, content: {
            Alert(title: Text("Permission Denied"), message: Text("Please Enable Permission In App Settings"), dismissButton: .default(Text("Go Setting"), action: {
                // Redireting User To Settings...
                UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)
            }))
        })
        .onChange(of: mapData.searchTxt, perform: { value in
            // Searching Places...
            // You can use your own delay time to avoid Continous Search Request...
            let delay = 0.3
            DispatchQueue.main.asyncAfter(deadline: .now() + delay) {
                if value == mapData.searchTxt {
                    // Search...
                    self.mapData.searchQuery()
                }
                
            }
            
        })
    }
    
    func regionToString(_ region: MKCoordinateRegion) -> String {
        "\(region.center.latitude), \(region.center.longitude)"
    }
}

struct Home_Previews: PreviewProvider {
    static var previews: some View {
        Home()
        
    }
}

MapView.swift

import SwiftUI
import MapKit

struct MapView: UIViewRepresentable {
    @EnvironmentObject var mapData: MapViewModel
    
    
    func makeCoordinator() -> Coordinator {
        return MapView.Coordinator(center: $mapData.center)
    }
    
    func makeUIView(context: Context) -> MKMapView {
        let view = mapData.mapView
        view.showsCompass = false
        view.showsUserLocation = true
        view.delegate = context.coordinator
        
        let compassBtn = MKCompassButton(mapView: view)
                compassBtn.frame.origin = CGPoint(x: 20, y: 100) // you may use GeometryReader to replace it's position
        compassBtn.compassVisibility = .adaptive // compass will always be on map
        view.addSubview(compassBtn)

        return view
        
    }
    
    func updateUIView(_ uiView: MKMapView, context: Context) {
        //
        print("Updating")
    
    }
    
    class Coordinator: NSObject,MKMapViewDelegate {
        @Binding var center: CLLocationCoordinate2D?
        
        init(center: Binding<CLLocationCoordinate2D?>) {
            self._center = center
        }
        
        func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
            // Custom Pins....
            // Excluding User Blue Circle...
            if annotation.isKind(of: MKUserLocation.self){return nil}
            else{
                let pinAnnotation = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "PIN_VIEW")
                pinAnnotation.tintColor = .red
                pinAnnotation.animatesDrop = true
                pinAnnotation.canShowCallout = true
                return pinAnnotation
            }
            
        }
        
        
        func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
            
            let currentLocation = mapView.centerCoordinate
                    print("👉 Координаты \(currentLocation)")
            center = currentLocation
        
        }
    
    }
}

MapViewModel.swift

import SwiftUI
import MapKit
import CoreLocation
// All Map Data Goes Here....
class MapViewModel: NSObject,ObservableObject,CLLocationManagerDelegate{
    @Published var center: CLLocationCoordinate2D?
    @Published var mapView = MKMapView()
// Region...
    @Published var region : MKCoordinateRegion!
    // Based On Location It Will Set Up....
// Alert...
    @Published var permissionDenied = false
    // Map Type...
    @Published var mapType : MKMapType = .standard
    // SearchText...
    @Published var searchTxt = ""
    // Searched Places...
    @Published var places : [Place] = []
    // Updating Map Type...
    func updateMapType(){
        if mapType == .standard{
            mapType = .hybrid
            mapView.mapType = mapType
        } else {
            mapType = .standard
            mapView.mapType = mapType
        }
    }
    // Focus Location...
    func focusLocation() {
        guard let _ = region else{return}
        mapView.setRegion(region, animated: true)
        mapView.setVisibleMapRect(mapView.visibleMapRect, animated: true)
    }
    // Search Places...
    func searchQuery(){
        places.removeAll()
        let request = MKLocalSearch.Request()
        request.naturalLanguageQuery = searchTxt
// Fetch...
        MKLocalSearch(request: request).start { (response, _) in
            guard let result = response else{return}
            self.places = result.mapItems.compactMap({ (item) -> Place? in
                return Place(placemark: item.placemark)
            })
        }
    }
    // Pick Search Result...
    func selectPlace(place: Place) {
        // Showing Pin On Map....
        searchTxt = ""
        guard let coordinate = place.placemark.location?.coordinate else{return}
        let pointAnnotation = MKPointAnnotation()
        pointAnnotation.coordinate = coordinate
        pointAnnotation.title = place.placemark.name ?? "No Name"
        // Removing All Old Ones...
        mapView.removeAnnotations(mapView.annotations)
        mapView.addAnnotation(pointAnnotation)
        // Moving Map To That Location...
        let coordinateRegion = MKCoordinateRegion(center: coordinate, latitudinalMeters: 10000, longitudinalMeters: 1000 )
        mapView.setRegion(coordinateRegion, animated: true)
        mapView.setVisibleMapRect(mapView.visibleMapRect, animated: true)
    }
    
    func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
        // Checking Permissions...
        switch manager.authorizationStatus {
        case .denied:
// Alert...
            permissionDenied.toggle()
        case .notDetermined:
            // Requesting....
            manager.requestWhenInUseAuthorization()
        case .authorizedWhenInUse:
            // If Permissin Given...
            manager.requestLocation()
        default:()
        }
    }
    
    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
// Error....
        print(error.localizedDescription)
    }
    // Getting user Region....
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.last else{return}
        self.region = MKCoordinateRegion(center: location.coordinate, latitudinalMeters: 10000, longitudinalMeters: 1000)
        // Updating Map....
        self.mapView.setRegion(self.region, animated: true)
        // Smooth Animations...
        self.mapView.setVisibleMapRect(self.mapView.visibleMapRect, animated: true)
        
        print(location.coordinate)
    }

}

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