我正面临一个MKMapView的奇怪问题.我使用过MKOverlayRenderer.现在的问题是当我缩小图像显示正确时.但是在放大的情况下,图像的某些部分会被切断.看起来MapView的一部分正在叠加层之上.以下是我的叠加渲染器代码.
class MapOverlayRenderer: MKOverlayRenderer {
var overlayImage: UIImage
var plan: Plan
init(overlay: MKOverlay,overlayImage: UIImage,plan: Plan) {
self.overlayImage = overlayImage
self.plan = plan
super.init(overlay: overlay)
}
override func draw(_ mapRect: MKMapRect,zoomScale: MKZoomScale,in ctx: CGContext) {
let theMapRect = overlay.boundingMapRect
let theRect = rect(for: theMapRect)
// Rotate around top left corner
ctx.rotate(by: CGFloat(degreesToRadians(plan.bearing)));
// Draw the image
UIGraphicsPushContext(ctx)
overlayImage.draw(in: theRect,blendMode: CGBlendMode.normal,alpha: 1.0)
UIGraphicsPopContext();
}
func degreesToRadians(_ x:Double) -> Double {
return (M_PI * x / 180.0)
}
}
虽然我不知道实际的原因,但是当我评论ctx.rotate(by :)函数时,这个问题已得到修复.但这不是我的解决方案,因为图像必须处于适当位置.
请尝试以下.
override func draw(_ mapRect: MKMapRect,in ctx: CGContext) {
DispatchQueue.main.async {
let theMapRect = overlay.boundingMapRect
let theRect = rect(for: theMapRect)
// Rotate around top left corner
ctx.rotate(by: CGFloat(degreesToRadians(plan.bearing)));
// Draw the image
UIGraphicsPushContext(ctx)
overlayImage.draw(in: theRect,alpha: 1.0)
UIGraphicsPopContext();
}
}
