在地图上选择注释时坐标为零Swift

Question

我正在更改我的应用程序的一部分，从 UITableview 中显示一些商店到 MKMapView 中显示它们并且它们显示正常但是当我 select地图上的注释。在 didAdd 中，我打印了它们，它们很好，事实上，注释显示在地图上。自从我上次使用 MapKit 以来已经有一段时间了，我无法确定问题是出在自定义注释 class 还是其他地方。你能发现我滥用它的地方吗？一如既往，非常感谢您的时间和帮助。这是注释 class:

class ShopAnnotation: NSObject , MKAnnotation {

    var title: String?
    var coordinate:CLLocationCoordinate2D
    var image: UIImage?
    var shopName: String?
    var shopLogoUrl: String?

    init(title: String, iconImage: UIImage, coordinate:CLLocationCoordinate2D, shopName: String, shopLogoUrl: String) {


        self.coordinate = coordinate
        self.title = title
        self.shopName = shopName
        self.shopLogoUrl = shopLogoUrl
        self.image = iconImage

    }
}

我有一个数组，我从中获取值：

var availableShopsArray:[(name:String, logoUrl:String, homeLat: String, homeLong: String)] = []

我循环遍历它并在地图上放置注释：

func displayShops() {
        mapView.removeAnnotations(mapView.annotations)

        for shop in availableShopsArray {
            let coordinates: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: Double(shop.homeLat)!, longitude: Double(shop.homeLong)!)
            let title = "Route Mid"
            let image = UIImage(named: title)!
            let shopAnn: ShopAnnotation = ShopAnnotation(title: title, iconImage: image, coordinate: coordinates, shopName: shop.name, shopLogoUrl: shop.logoUrl)
            mapView.addAnnotation(shopAnn)
        }
//        self.availableShopsTableview.reloadData()
    }

当我 select 一个时，我应该从中获取值，但坐标为零：

func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
        guard let selectedShop = view.annotation as? ShopAnnotation else {return}
        self.shopLogoUrl = selectedShop.shopLogoUrl!
        self.selectedShopCoordinates.latitude = selectedShop.coordinate.latitude
        self.selectedShopCoordinates.longitude = selectedShop.coordinate.longitude
        self.selectedShopName = selectedShop.shopName

//        calculateBookingType()
        self.performSegue(withIdentifier: "bookingToCartSegue", sender: self)
    }

这是 viewForAnnotation :

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? { // rajish version
        let annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "")

        if annotation is MKUserLocation{
            return nil
        } else {
            print("Annotation.coordinates are: \(String(describing: annotation.coordinate))")
//            print("annotation title is: \(String(describing: annotation.title!))")
            annotationView.image = UIImage(named:(annotationView.annotation?.title)! ?? "")

            annotationView.canShowCallout = true
            let transform = CGAffineTransform(scaleX: 0.27, y: 0.27) // alert annotation's icons size
            annotationView.transform = transform
            // makin allerts draggable
            annotationView.isDraggable = false
            return annotationView
        }
    }

Answer 1

奇怪的是，我将纬度和经度分别分配给 selectedShop.coordinate 和 selectedShopCoordinates，然后它会找到 nil。我现在将它们分配为 selectedShopCoordinates = selectedShop.coordinate 的坐标并且不再崩溃了。

为什么它会在单个坐标度上找到nil，这仍然是个谜。任何关于为什么的想法将不胜感激。希望这会帮助其他人挣扎。干杯

在地图上选择注释时坐标为零Swift

Coordinates are nil when selecting annotation on map Swift

mapkit

mkannotation

mkannotationview

ios

swift