UIImage 上的 MapKit 功能，删除 pins/Annotation

Question

我正在尝试在图像上使用现有的 MapKit 功能。我想要实现的是在图像上放置图钉，并可能在这些图钉上添加注释。我已经设法让用户可以使用 longGesture 动态添加图钉，但我不知道如何在图像上实现相同的效果。

我的代码如下：

import UIKit
import MapKit

class ViewController: UIViewController , MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!
    var keyLat:String = "49.2768"
    var keyLon:String = "-123.1120"
    @IBOutlet weak var image: UIImageView!
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        mapView.delegate = self
        
        let longPressRecogniser = UILongPressGestureRecognizer(target: self, action: #selector(self.handleTap(_:)))
        longPressRecogniser.minimumPressDuration = 0.5
        mapView.addGestureRecognizer(longPressRecogniser)
        
        mapView.mapType = MKMapType.standard
        
        let location = CLLocationCoordinate2D(latitude: CLLocationDegrees(keyLat.toFloat()),longitude: CLLocationDegrees(keyLon.toFloat()))
        
        let span = MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)
        let region = MKCoordinateRegion(center: location, span: span)
        mapView.setRegion(region, animated: true)
        
        let annotation = MKPointAnnotation()
        annotation.coordinate = location
        annotation.title = "MY Pin"
        annotation.subtitle = "On the Map"
        mapView.addAnnotation(annotation)
    }

    
    @objc func handleTap(_ gestureReconizer: UILongPressGestureRecognizer)
    {
        
        let location = gestureReconizer.location(in: mapView)
        let coordinate = mapView.convert(location,toCoordinateFrom: mapView)
        
        // Add annotation:
        let annotation = MKPointAnnotation()
        annotation.coordinate = coordinate
        annotation.title = "latitude:" + String(format: "%.02f",annotation.coordinate.latitude) + "& longitude:" + String(format: "%.02f",annotation.coordinate.longitude)
        mapView.addAnnotation(annotation)
        
    }
    
    
    var selectedAnnotation: MKPointAnnotation?
    
    func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
        
        let latValStr : String = String(format: "%.02f",Float((view.annotation?.coordinate.latitude)!))
        let lonvalStr : String = String(format: "%.02f",Float((view.annotation?.coordinate.longitude)!))
        
        print("latitude: \(latValStr) & longitude: \(lonvalStr)")
    }
    
}

任何帮助将不胜感激。谢谢乔治

Answer 1

通过遵循相同的过程并在此处和那里进行一些调整，可以实现相同的效果。我制作了一个示例 ViewController，演示了如何将指针（在本例中为 UIViews）添加到 UIImageView.

class ViewController: UIViewController {

    @IBOutlet weak var imageView: UIImageView! // Image view

    lazy var longPress = UILongPressGestureRecognizer(target: self, action: #selector(didLongPressScreen)) // long press gesture

    // MARK: LifeCycle
    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        setup()
    }

    // MARK: Functions
    private func setup() {
        imageView.image = UIImage(named: "photo")

        imageView.addGestureRecognizer(longPress) // Adding gesture recognizer 
        imageView.isUserInteractionEnabled = true // ImageViews are not user interactive by default

    }

    // UILongPressGestureRecognizer Action
    @objc func didLongPressScreen(_ sender: UILongPressGestureRecognizer) {
        let location = sender.location(in: self.view) //Getting location

        DispatchQueue.main.async {
            let pointer = UIView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
            pointer.backgroundColor = .red
            pointer.center = location // Setting the center of the view to the x,y coordinates of the long press
            self.view.addSubview(pointer) // Adding the UIView to the view
        }
    }
}

其中最重要的部分是为 UIImageView 启用用户交互。 isUserInteractionEnabled 默认设置为 false。上面的输出可以在下面看到，

UIImage 上的 MapKit 功能，删除 pins/Annotation

MapKit functionality on a UIImage, dropping pins/Annotation

swift

uiimageview

mapkit

mapkitannotation