Question

我正在尝试使用以下代码在地图上绘制多边形但由于某种原因它无法正常工作。我在这里出了什么问题？

import UIKit
import MapKit

class ViewController: UIViewController {

    @IBOutlet weak var mapView: MKMapView!
    override func viewDidLoad() {
        super.viewDidLoad()
        let initialLocation = CLLocation(latitude: 49.140838, longitude: -123.127886)
        centerMapOnLocation(initialLocation)
        addBoundry()
    }


    func addBoundry()
    {
        var points=[CLLocationCoordinate2DMake(49.142677,  -123.135139),CLLocationCoordinate2DMake(49.142730, -123.125794),CLLocationCoordinate2DMake(49.140874, -123.125805),CLLocationCoordinate2DMake(49.140885, -123.135214)]

        let polygon = MKPolygon(coordinates: &points, count: points.count)

        mapView.addOverlay(polygon)
    }


    let regionRadius: CLLocationDistance = 1000
    func centerMapOnLocation(location: CLLocation) {
        let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
            regionRadius * 2.0, regionRadius * 2.0)
        mapView.setRegion(coordinateRegion, animated: true)
    }


}


func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
        if overlay is MKPolygon {
        let polygonView = MKPolygonRenderer(overlay: overlay)
        polygonView.strokeColor = UIColor.magentaColor()

        return polygonView
    }

    return nil
}

Answer 1

您似乎已将mapView(_:renderFor:)（以前称为rendererForOverlay）实施为全局功能。该方法必须在ViewController类定义范围内，或者更好的是，在MKMapViewDelegate扩展名中保持我们的代码组织良好：

extension ViewController: MKMapViewDelegate {
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        ...
    }
}

此外，请确保您已将视图控制器定义为地图视图的delegate。在IB中这样做可能最容易，但您也可以在viewDidLoad中执行此操作：

mapView.delegate = self

如何使用MapKit和swift绘制多边形叠加层

1 个答案: