Swiftui 使用Pin将坐标传递到地图视图

我正在尝试在地图上显示地图pin。输入交易后，详细信息将与位置坐标一起保存。在交易条目列表中，用户可以单击条目以获取更多详细信息，包括显示交易位置的小地图

根据Asperi的建议，似乎我需要声明一个可识别的结构，以便使用地图pin

在DetailView中，纬度和经度将在传输到MapView之前复制到坐标参数

struct DetailView: View {
       
    var coordinate: CLLocationCoordinate2D {
          CLLocationCoordinate2D(
          latitude: item.entryLat,
          longitude: item.entryLong)
     }
        
        var body: some View {
            
            VStack {
                MapView(coordinate: coordinate)
                    .ignoresSafeArea(edges: .all)
                    .frame(height: 400)
                    .padding(.vertical, 10)
            }
       }
  }

MapView是我遇到麻烦的地方。我不确定如何输入区域和标记（xxxxx）的坐标。将`坐标复制到@State区域和标记会产生错误“传递给不带参数的调用的参数”

---

听起来对于您的应用程序来说，将区域声明为常量是可行的。代码如下所示：

struct Marker: Identifiable {
    let id = UUID()
    var location: MapMarker
}

struct MapView: View {
    var coordinate: CLLocationCoordinate2D
    
    var body: some View {
        
        Map(coordinateRegion: .constant(MKCoordinateRegion(center: coordinate,
                                                           span: MKCoordinateSpan(latitudeDelta: 0.5, longitudeDelta: 0.5))),
            showsUserLocation: true,
            annotationItems: [Marker(location: MapMarker(coordinate: coordinate))]) { marker in
                marker.location
        }.edgesIgnoringSafeArea(.all)
    }
}

如果仍希望将其用作@State变量，则可以使用自定义

init

来设置该值：

struct MapView: View {
    var coordinate: CLLocationCoordinate2D
    
    @State private var region : MKCoordinateRegion
    
    init(coordinate : CLLocationCoordinate2D) {
        self.coordinate = coordinate
        _region = State(initialValue: MKCoordinateRegion(center: coordinate,
                                                             span: MKCoordinateSpan(latitudeDelta: 0.5, longitudeDelta: 0.5)))
    }
    
    var body: some View {
        Map(coordinateRegion: $region,
            showsUserLocation: true,
            annotationItems: [Marker(location: MapMarker(coordinate: coordinate))]) { marker in
                marker.location
        }
        .edgesIgnoringSafeArea(.all)
    }
}

最后，我将内联定义markers数组，但您可以将其拆分为一个计算属性：

    var markers : [Marker] {
        [Marker(location: MapMarker(coordinate: coordinate))]
    }
    
    var body: some View {
        Map(coordinateRegion: $region,
            showsUserLocation: true,
            annotationItems: markers) { marker in
                marker.location
        }
        .edgesIgnoringSafeArea(.all)
    }

---

感谢jnpdx，前两个选项非常有效！

    var markers : [Marker] {
        [Marker(location: MapMarker(coordinate: coordinate))]
    }
    
    var body: some View {
        Map(coordinateRegion: $region,
            showsUserLocation: true,
            annotationItems: markers) { marker in
                marker.location
        }
        .edgesIgnoringSafeArea(.all)
    }