Question

我正在尝试在WKInterfaceMap的{{1}}对象的特定区域（例如美国）上添加图像叠加层。在使用MKMapView的iOS中，我可以将图像叠加层添加为：

我有两个自定义类Watchkit和ImageOverlay

ImageOverlayRenderer

ImageOverlayRenderer

class ImageOverlay: NSObject, MKOverlay {

(topLeftCoordinate: CLLocationCoordinate2D, bottomRightCoordinate: CLLocationCoordinate2D,
     topRightCoordinate: CLLocationCoordinate2D, bottomLeftCoordinate:CLLocationCoordinate2D
     ) {
       // set coordinates here
    }

    var midPointCoordinate: CLLocationCoordinate2D {
    get {
        return CLLocationCoordinate2D(latitude: (topLeftCoordinate.latitude + bottomRightCoordinate.latitude)/2, longitude: (topLeftCoordinate.longitude + bottomRightCoordinate.longitude)/2)
    }
}

func overlayBoundingMapRect() -> MKMapRect {
    let topLeft = MKMapPointForCoordinate(self.topLeftCoordinate)
    let topRight = MKMapPointForCoordinate(self.topRightCoordinate)
    let bottomLeft = MKMapPointForCoordinate(self.bottomLeftCoordinate)
    let bottomRight = MKMapPointForCoordinate(self.bottomRightCoordinate)


    return MKMapRectMake(topLeft.x,
                         topLeft.y,
                         fabs(topLeft.x - topRight.x),
                         fabs(((topLeft.y + topRight.y) / 2.0 ) - ((bottomLeft.y + bottomRight.y) / 2.0 )));
}

//MKOverlay protocol

var boundingMapRect: MKMapRect {
    return overlayBoundingMapRect()
}

var coordinate: CLLocationCoordinate2D {
    return midPointCoordinate
}

}

这是我使用这些类渲染叠加层的方式：

class ImageOverlayRenderer: MKOverlayRenderer {
    init(overlay: MKOverlay, overlayImages: [UIImage]) {
    self.overlayImages = overlayImages[0]
    super.init(overlay: overlay)
}

override func draw(_ mapRect: MKMapRect, zoomScale: MKZoomScale, in context: CGContext) {
        let imageReference: CGImage = self.overlayImages[0].cgImage!;

        let theMapRect: MKMapRect = self.overlay.boundingMapRect;
        let theRect: CGRect = rect(for: theMapRect);

        context.scaleBy(x: 1.0, y: -1.0);
        context.translateBy(x: 0.0, y: -theRect.size.height);
        context.draw(imageReference, in: theRect);

}

}

MKMapView代表将此绘制为：

var circleMapView : MKMapView()
var mapImageOverlay : ImageOverlay?
var circleMapImageRenderer : ImageOverlayRenderer?

// fix coordinates to cover US region
let topLeft = CLLocationCoordinate2D(latitude: topLeftCoordinate.0, longitude: topLeftCoordinate.1)
let bottomRight = CLLocationCoordinate2D(latitude: bottomRightCoordinate.0, longitude: bottomRightCoordinate.1)

let topRight = CLLocationCoordinate2D(latitude: topRightCoordinate.0, longitude: topRightCoordinate.1)
let bottomLeft = CLLocationCoordinate2D(latitude: bottomLeftCoordinate.0, longitude: bottomLeftCoordinate.1)

 mapImageOverlay = ImageOverlay(topLeftCoordinate: topLeft , bottomRightCoordinate: bottomRight, topRightCoordinate:topRight, bottomLeftCoordinate: bottomLeft)

if let overlay = mapImageOverlay {
        circleMapView.insert(overlay, at: 0)
    }

这完美地在我设置的坐标上绘制图像！我的问题是：

如何使用这种技术或类似的方法来渲染func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer { if overlay is ImageOverlay { let renderer = ImageOverlayRenderer(overlay: imageOverlay, overlayImages: imgs) circleMapImageRenderer = renderer return renderer } return MKOverlayRenderer(overlay: overlay) }中的叠加层。根据我对SO线程，谷歌搜索和Apple文档的研究，我们可以在WatchKit WKInterfaceMap中使用WKInterfaceMap在特定的location上添加有限的注释，例如图钉或图像。我必须在一个区域上添加覆盖（例如美国）。请让我知道在centerOffSet当前环境中是否可行。

任何想法或方向将不胜感激。

如何在WKInterfaceMap中通过MapRect设置图像叠加层

0 个答案: