我在
Swift中有以下代码将MKPolyline添加到MapView. XCode没有告诉我有一个问题,据我所知,这应该是有效的.
MapView的插座：
@IBOutlet weak var mapView: MKMapView!
用于保持坐标的变量：
var coordinates: [CLLocationCoordinate2D] = []
从Core Data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Core Data中的坐标添加到我的新数组中：
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)
}
创建折线：
var polyLine = MKPolyline(coordinates: &coordinates,count: coordinates.count)
添加叠加层：
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,所以我知道数据已被添加.有任何想法吗？
