带孔的Google-SDK-iOS多边形

Hy, i am trying to achieve this, but in iOS:

Hy，我正在努力实现这一目标，但在iOS中：

甜甜圈谷歌地图Android

Basically the main idea is to have a zone highlighted and the rest faded. This is a requested feature in the Google-SDk-iOS, https://code.google.com/p/gmaps-api-issues/issues/detail?id=5464

基本上主要的想法是突出显示区域，其余区域消失。这是Google-SDk-iOS中的请求功能，https：//code.google.com/p/gmaps-api-issues/issues/detail？id = 5464

So far what i've done:

到目前为止我做了什么：

Set the mapview alpha to a low value (Transparency)
将mapview alpha设置为较低的值（透明度）
Draw a simple circle using google sdk GMSCircle on that view
在该视图上使用google sdk GMSCircle绘制一个简单的圆圈

But what this achieves is the inside of the circle also fades out. Any ideas or workarounds would me much appreciated, thank you.

但这实现了圆圈的内部也逐渐消失。我非常感谢任何想法或变通方法，谢谢。

1 个解决方案

#1

Unfortunately, you can not make a hole in GMSPolygon for iOS yet, this feature is only available in Android.

不幸的是，你不能在iOS的GMSPolygon上搞错，这个功能仅在Android中可用。

A workaround will be using pointForCoordinate() method from GMSProjection class. This method can convert a Earth coordinate to a point in your application's window.

解决方法是使用GMSProjection类中的pointForCoordinate（）方法。此方法可以将地球坐标转换为应用程序窗口中的某个点。

Also, in order to make the hole transparent, you probably need to use CAShapeLayer in your view. You can see more details in this * answer.

此外，为了使孔透明，您可能需要在视图中使用CAShapeLayer。您可以在此*答案中查看更多详细信息。

Sample code:

示例代码：

class ViewController: UIViewController, GMSMapViewDelegate {

    var mapView: GMSMapView!

    override func viewDidLoad() {
        super.viewDidLoad()
        let camera = GMSCameraPosition.cameraWithLatitude(-33.86,
            longitude: 151.20, zoom: 10)
        mapView = GMSMapView.mapWithFrame(CGRectZero, camera: camera)
        mapView.myLocationEnabled = true
        self.view = mapView

        self.mapView.delegate = self
    }

    func mapView(mapView: GMSMapView!, didChangeCameraPosition position: GMSCameraPosition!) {
        let point = mapView.projection.pointForCoordinate(CLLocationCoordinate2DMake(-33.86, 151.20))
        print("the screen point: \(point.x) \(point.y)")


        for subview in view.subviews {
            if subview.tag == 1 {
                subview.layer.mask = nil
                createHole(subview, holeX: point.x, holeY: point.y, radius: 100)
            }
        }
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)

        let overlayView = UIView(frame: view.bounds)
        overlayView.tag = 1
        overlayView.alpha = 0.6
        overlayView.backgroundColor = UIColor.blackColor()
        overlayView.userInteractionEnabled = false
        self.view.addSubview(overlayView)
    }


    func createHole(overlayView : UIView, holeX : CGFloat, holeY : CGFloat, radius: CGFloat)
    {
        let maskLayer = CAShapeLayer()

        // Create a path with the rectangle in it.
        let path = CGPathCreateMutable()

        CGPathAddArc(path, nil, holeX, holeY, radius, 0.0, 2 * 3.14, false)
        CGPathAddRect(path, nil, CGRectMake(0, 0, overlayView.frame.width, overlayView.frame.height))

        maskLayer.backgroundColor = UIColor.blackColor().CGColor

        maskLayer.path = path;
        maskLayer.fillRule = kCAFillRuleEvenOdd

        overlayView.layer.mask = maskLayer
        overlayView.clipsToBounds = true
    }
}

#1