2

我想根据路线方向旋转标记图像。我已经使用 Map box SDK 实现了地图。坐标和方向是通过网络服务获取的。我尝试了 imageForMarker 但它没有用。实现如下

func mapView(_ mapView: MGLMapView, imageFor annotation: MGLAnnotation) -> MGLAnnotationImage? {

    let img = imageRotatedByDegrees(oldImage: UIImage(named: "car")!, deg: CGFloat(self.bearing))

    return MGLAnnotationImage(image: img, reuseIdentifier: "car")
}
func imageRotatedByDegrees(oldImage: UIImage, deg degrees: CGFloat) -> UIImage
{
    let size = oldImage.size

    UIGraphicsBeginImageContext(size)

    let bitmap: CGContext = UIGraphicsGetCurrentContext()!
    //Move the origin to the middle of the image so we will rotate and scale around the center.
    bitmap.translateBy(x: size.width / 2, y: size.height / 2)
    //Rotate the image context
    bitmap.rotate(by: (degrees * CGFloat(Double.pi / 180)))
    //Now, draw the rotated/scaled image into the context
    bitmap.scaleBy(x: 1.0, y: -1.0)

    let origin = CGPoint(x: -size.width / 2, y: -size.width / 2)

    bitmap.draw(oldImage.cgImage!, in: CGRect(origin: origin, size: size))

    let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return newImage
}
4

2 回答 2

0

似乎正确的方法是使用带有注释的 MGLSymbolStyleLayer，而不是直接添加注释并使用 mapview 委托方法：https ://www.mapbox.com/ios-sdk/api/3.6.2/类/MGLSymbolStyleLayer.html#/c:objc(cs)MGLSymbolStyleLayer(py)iconRotation

您可以使用一个 iconRotation 属性来获取度数。

这很不幸，因为我的用例有几个相同的图像但标题不同，所以我必须为每个图像添加一个图层。

于 2018-02-19T21:22:10.563 回答
0

尝试使用自定义重用标识符，如下所示：

func mapView(_ mapView: MGLMapView, imageFor annotation: MGLAnnotation) -> MGLAnnotationImage? {
    let annotation = annotation as! CustomMapAnnotation

    var annotationImage = mapView.dequeueReusableAnnotationImage(withIdentifier: annotation.id)

    if annotationImage == nil {
        var image = UIImage(named: "taxi")!

        if let heading = annotation.heading {
            image = image.imageRotatedByDegrees(degrees: heading)
        }
        image = image.withAlignmentRectInsets(UIEdgeInsets(top: 0, left: 0, bottom: image.size.height/2, right: 0))

        annotationImage = MGLAnnotationImage(image: image, reuseIdentifier: annotation.id)
    }

    return annotationImage
}
于 2017-10-12T20:53:43.600 回答