在 MapView 中检测 SwiftUI 的长按

Question

我在 SwiftUi 中有一个 MapView，当用户长按 map 上的位置时，我正在尝试为其添加引脚注释。 我看到这可以在 swift 中轻松完成，但是我使用的是 SwiftUI。 我不知道如何添加长按检测器。 一个代码示例会很棒。

我的地图视图

struct MapView: UIViewRepresentable {

@Binding
var annotations: [PinAnnotation]
let addAnnotationListener: (PinAnnotation) -> Void

func makeUIView(context: Context) -> MKMapView {
    let mapView = MKMapView()
    mapView.delegate = context.coordinator
    return mapView
}

func updateUIView(_ view: MKMapView, context: Context) {
    view.delegate = context.coordinator
    view.addAnnotations(annotations)
    if annotations.count == 1 {
        let coords = annotations.first!.coordinate
        let region = MKCoordinateRegion(center: coords, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))
        view.setRegion(region, animated: true)
    }

}


func makeCoordinator() -> MapViewCoordinator {
    MapViewCoordinator(self)
}

}

地图视图协调器

class MapViewCoordinator: NSObject, MKMapViewDelegate {

var mapViewController: MapView

init(_ control: MapView) {
    self.mapViewController = control
}

func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {
    let annotation = view.annotation
    guard let placemark = annotation as? MKPointAnnotation else { return }
}

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView?{
    //Custom View for Annotation
    let identifier = "Placemark"
    if  let annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) {
        annotationView.annotation = annotation
        return annotationView
    } else {
        let annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
        annotationView.isEnabled = true
        annotationView.canShowCallout = true
        let button = UIButton(type: .infoDark)
        annotationView.rightCalloutAccessoryView = button
        return annotationView
    }
}
}

将图钉添加到 MapView 的方法

    func addPinBasedOnGesture(gestureRecognizer:UIGestureRecognizer){
        var touchPoint = gestureRecognizer.locationInView(mapView)
        var newCoordinates = self.convertPoint(touchPoint, toCoordinateFromView: mapView)
        let annotation = MKPointAnnotation()
        annotation.coordinate = newCoordinates
        mapView.addAnnotation(annotation)
    }

Answer 1

下面的解决方案在用户长按 Map 的位置添加了一个引脚。

在MapViewCoordinator中添加以下方法

@objc func addPinBasedOnGesture(_ gestureRecognizer:UIGestureRecognizer) {
    let touchPoint = gestureRecognizer.location(in: gestureRecognizer.view)
    let newCoordinates = (gestureRecognizer.view as? MKMapView)?.convert(touchPoint, toCoordinateFrom: gestureRecognizer.view)
    let annotation = PinAnnotation()
    guard let _newCoordinates = newCoordinates else { return }
    annotation.coordinate = _newCoordinates
    mapViewController.annotations.append(annotation)
}

和func makeUIView(context: Context) -> MKMapView {}中的 longPress 手势代码

    func makeUIView(context: Context) -> MKMapView {
    let mapView = MKMapView()
    mapView.delegate = context.coordinator
    let longPressed = UILongPressGestureRecognizer(target: context.coordinator,
                                                   action: #selector(context.coordinator.addPinBasedOnGesture(_:)))
    mapView.addGestureRecognizer(longPressed)
    return mapView
}

Answer 2

在下面找到提供的代码的修改部分以获得所需的行为：

struct SUMapView: UIViewRepresentable {

    // ... other your code here

    func makeUIView(context: Context) -> MKMapView {
        let mapView = MKMapView()
        mapView.delegate = context.coordinator

        let longPressed = UILongPressGestureRecognizer(target: 
              context.coordinator, action: #selector(addPin(gesture:)))
        mapView.addGestureRecognizer(longPressed)

        return mapView
    }

    // ... other your code here
}

class MapViewCoordinator: NSObject, MKMapViewDelegate {

    // ... other your code here

    @objc func addPin(gesture: UILongPressGestureRecognizer) {
        // do whatever needed here
    }

    // ... other your code here

}