ios - 在 iOS map 上有条件地给 MKCircle 上色

Question

我需要显示一个由圆形和多边形组成的 map ，每个圆形或多边形可能有不同的颜色。

我最初的计划是子类化 MKCircle 和 MKPolygon 并为我的 Region 类添加一个实例变量(其中包含将确定 map 上形状颜色的信息)但是不可能将其中任何一个子类化

有什么想法吗？

这是我目前所拥有的:

// draw the regions
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
    if overlay is MKCircle {
        // display circles on the map
        let circle = MKCircleRenderer(overlay: overlay)


        circle.strokeColor = UIColor.red // THIS SHOULD BE CONDITIONAL (sometimes red, sometimes green -> depends on a class that I have called region)
        circle.fillColor = UIColor(red: 255, green: 0, blue: 0, alpha: 0.1)
        circle.lineWidth = 1
        return circle
    } else if overlay is MKPolygon {
        // display polygons on the map
        let poly = MKPolygonRenderer(overlay: overlay)
        poly.strokeColor = UIColor.red // THIS SHOULD BE CONDITIONAL (sometimes red, sometimes green -> depends on a class that I have called region)
        poly.fillColor = UIColor(red: 255, green: 0, blue: 0, alpha: 0.1)
        poly.lineWidth = 1
        return poly
    } else {
        return MKPolylineRenderer()
    }
}

Answer 1

我知道这是一个旧线程，但我想我会分享我是如何做到的

我使用扩展的存储属性来创建一个变量，该变量可以区分 MKCircle 是针对成员还是我需要的地方

示例代码如下:

extension MKCircle {
    
    enum type {
        case place
        case member
    }
    
    private static var savedCircleType: type = .member
    
    var circleType : type {
        get{
            return MKCircle.savedCircleType
        }
        set(newValue) {
            MKCircle.savedCircleType = newValue
        }
    }
    
}

添加注解时，这样做

let circle = MKCircle(center: currentLocationPin.coordinate, radius: 200)
circle.circleType = .member // or .place in my case
self.mapView.addOverlay(circle)
self.mapView.addAnnotation(currentLocationPin)

最后在 MKMapView 委托(delegate)中

func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        if overlay is MKCircle {
            let circleRenderer = MKCircleRenderer(overlay: overlay)
            let color: UIColor = (circleRenderer.circle.circleType == .place) ? .themeGreen : .red
            circleRenderer.strokeColor = color
            circleRenderer.fillColor = color.withAlphaComponent(0.3)
            circleRenderer.lineWidth = 2.0
            return circleRenderer
        } else {
            return MKPolylineRenderer()
        }
    }

结果: /image/ApH9I.jpg