我有以下 Objective-C 方法:
- (void)addPolygonToMap {
NSInteger numberOfPoints = [self.coordinates count];
if (numberOfPoints > 4) {
CLLocationCoordinate2D points[numberOfPoints];
for (NSInteger i = 0; i < numberOfPoints; i++) {
points[i] = [self.coordinates[i] MKCoordinateValue];
}
self.polygon = [MKPolygon polygonWithCoordinates:points count:numberOfPoints];
[self.mapView addOverlay: self.polygon];
}
self.isDrawingPolygon = NO;
[self.drawPolygonButton setTitle:@"draw" forState:UIControlStateNormal];
self.canvasView.image = nil;
[self.canvasView removeFromSuperview];
}
我尝试将其转换为 Swift:
func addPolygonToMap() {
var numberOfPoints: NSInteger = self.coordinates.count
if (numberOfPoints > 4) {
var points: [CLLocationCoordinate2D] = []
var coordsPointer = UnsafeMutablePointer<CLLocationCoordinate2D>.alloc(numberOfPoints)
for i in 0..<numberOfPoints {
points.append(coordsPointer[i])
}
self.polygon = MKPolygon(coordinates: &points, count: numberOfPoints)
self.mapView.addOverlay(self.polygon)
coordsPointer.dealloc(numberOfPoints)
}
self.isDrawingPolygon = false
self.drawPolygonButton.setTitle("Draw", forState: .Normal)
self.canvasView.image = nil
self.canvasView.removeFromSuperview()
}
最后,当委托(delegate)方法被调用时,它实际上并没有添加 overlay
到 mapView
.我什么也看不见。
我假设这是我的 self.addPolytonToMap()
方法,但我不是 100% 确定。整个场景在我的 Objective-C 项目中运行良好。
func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
if (overlay is MKPolygon) {
var overlayPathView = MKPolygonRenderer(overlay: overlay)
overlayPathView.fillColor = UIColor.cyanColor().colorWithAlphaComponent(0.2)
overlayPathView.strokeColor = UIColor.cyanColor().colorWithAlphaComponent(0.2)
overlayPathView.lineWidth = 5
return overlayPathView
} else if (overlay is MKPolyline) {
var overlayPathView = MKPolylineRenderer(overlay: overlay)
overlayPathView.strokeColor = UIColor.blueColor().colorWithAlphaComponent(0.7)
overlayPathView.lineWidth = 5
return overlayPathView
}
return nil
}
更新:
我刚刚注意到在我的 Objective-C 版本中,points[i].latitude
一切顺利,但是当我执行以下操作时,我得到了一个奇怪的输出:
println(coordsPointer[i].latitude)
输出:
1.63041663127611e-321
1.64523860065135e-321
1.65511991356818e-321
1.68970450877706e-321
1.7045264781523e-321
1.72922976044436e-321
这可以解释为什么我没有看到 overlay
, 但是我对 UnsafeMutablePointer<>
的体验是有限的。
最佳答案
通过修改 addPolygonToMap()
方法修复:
func addPolygonToMap() {
var numberOfPoints: NSInteger = self.coordinates.count
if (numberOfPoints > 4) {
var points: [CLLocationCoordinate2D] = []
for i in 0..<numberOfPoints {
points.insert(self.coordinates[i].MKCoordinateValue, atIndex: i)
}
self.polygon = MKPolygon(coordinates: &points, count: numberOfPoints)
self.mapView.addOverlay(self.polygon)
}
self.isDrawingPolygon = false
self.drawPolygonButton.setTitle("Draw", forState: .Normal)
self.canvasView.image = nil
self.canvasView.removeFromSuperview()
}
感谢 @Volker 的帮助。
关于objective-c - 将 MKPolygon Objective-C 代码转换为 Swift,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/28208535/