为什么MKPolyline没有显示在我的应用程序中?
问题描述:
我正在尝试创建一个应用程序,其功能之一是在用户移动时绘制线条。为什么MKPolyline没有显示在我的应用程序中?
这里是类
class traceuserViewController: UIViewController,CLLocationManagerDelegate, MKMapViewDelegate {
var locationManager = CLLocationManager()
var startLocation: CLLocation?
var endLocation: CLLocation?
@IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
self.locationManager.distanceFilter = 30.0
self.locationManager.startMonitoringSignificantLocationChanges()
self.locationManager.startUpdatingLocation()
mapView.showsUserLocation = true
mapView.mapType = .hybrid
self.mapView.delegate = self
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
//user's current location
let nowlocation = locations.last
userLocations.append(nowlocation!)
print("HERE IS THE LOCATION ARRAY")
print(userLocations)
//show the current location region
let center = CLLocationCoordinate2D(latitude: nowlocation!.coordinate.latitude, longitude: nowlocation!.coordinate.longitude)
let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.7, longitudeDelta: 0.7))
self.mapView.setRegion(region, animated: true)
drawRoute(locationArray: userLocations)
}
func drawRoute(locationArray: [CLLocation]) {
if (locationArray.count) > 1 {
var destinationLocIndex = (locationArray.count) - 1
var startLocIndex = (locationArray.count) - 2
let destinationloc = locationArray[destinationLocIndex].coordinate
let startLoc = locationArray[startLocIndex].coordinate
var routeArray = [startLoc, destinationloc]
//test if the function works well or not
print(routeArray)
var geodesicLine = MKGeodesicPolyline(coordinates: routeArray , count: routeArray.count)
mapView.add(geodesicLine, level: .aboveRoads)
}
}
//draw in the mapview
private func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer! {
if overlay is MKPolyline{
let polylineRenderer = MKPolylineRenderer(overlay: overlay)
polylineRenderer.strokeColor = UIColor.blue
polylineRenderer.lineWidth = 5.0
return polylineRenderer
}else{
os_log("Failed to draw the polyline", log: OSLog.default, type: .debug)
return nil
}
}
多次尝试后,我仍然不知道为什么它不画,当用户移动地图上的路线,任何人都可以请我有我一些提示?
欢呼
答
我推断你使用的斯威夫特3从代码片段(例如中didUpdateLocations
签名;使用.hybrid
而非雨燕2.3的.Hybrid
;等等)。
但是,mapView(_:rendererFor:)
的签名不正确。在斯威夫特3,它是:
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
...
}
如果你曾经有没有出现工作委托方法,它添加一个断点,可以确认,如果这就是所谓的全部或没有(如果是称为,你可以通过它并进一步诊断问题)。
是的,它现在正在工作!非常感谢:P – Jenny