我在Swift中有以下代码,可以将MKPolyline添加到MapView中。XCode并没有告诉我有问题,据我所读,这应该是有效的。
MapView出口:
@IBOutlet weak var mapView: MKMapView!
保存坐标的变量:
var coordinates: [CLLocationCoordinate2D] = []
从核心数据获取我保存的坐标:
var contextMap = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext!
var requestMap = NSFetchRequest(entityName: "Locations")
let predMap = NSPredicate(format: "game = %d", passedGameNumber)
requestMap.predicate = predMap
requestMap.sortDescriptors = [NSSortDescriptor(key:"time", ascending: false)]
self.locationsList = contextMap.executeFetchRequest(requestMap, error: nil)! as [Locations]
将核心数据中的坐标添加到我的新数组:
for index in 1..<self.locationsList.count{
var lat = Double(self.locationsList[index].latitude)
var long = Double(self.locationsList[index].longitude)
var coordinatesToAppend = CLLocationCoordinate2D(latitude: lat, longitude: long)
coordinates.append(coordinatesToAppend)
}
创建多段线:
var polyLine = MKPolyline(coordinates: &coordinates, count: coordinates.count)
添加覆盖:
self.mapView.addOverlay(polyLine, level: MKOverlayLevel.AboveRoads)
将其添加到MapView:
func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
if overlay.isKindOfClass(MKPolyline) {
// draw the track
let polyLine = overlay
let polyLineRenderer = MKPolylineRenderer(overlay: polyLine)
polyLineRenderer.strokeColor = UIColor.blueColor()
polyLineRenderer.lineWidth = 2.0
return polyLineRenderer
}
return nil
}
我只是得到一个空白的MapView。我可以将坐标数组打印到控制台,这样我就知道数据已经添加。有什么想法吗?
以上方法在Swift3:中会这样写
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
if overlay.isKind(of: MKPolyline.self) {
// draw the track
let polyLine = overlay
let polyLineRenderer = MKPolylineRenderer(overlay: polyLine)
polyLineRenderer.strokeColor = UIColor.blue
polyLineRenderer.lineWidth = 2.0
return polyLineRenderer
}
return MKPolylineRenderer()
}
正如评论中所说,问题中的代码很好。我只是没有设置代理。
mapView.delegate = self