ios - 根据用户位置绘制折线 [SWIFT]

Question

我创建了一个应用程序，其中我使用 (MapKit) 制作了一张 map ，当我按下“开始”时，它会自动放大到我的位置并放置注释。

但是从这里开始，我很困惑。我正在尝试从起始位置到当前位置绘制一条折线。 (并更新我所做的每一个 Action )。因此，举个例子，如果我向北步行 300 米，我应该能够在手机上查看 map 并看到多边形线在跟随我。

所以从注解开始----->(Polyline)到User。并始终保持更新(这样你就可以看到线在移动

我怎样才能做到这一点？如果你知道，请在评论中告诉我。我会非常感谢它! :)

在正确位置添加注解的代码:

@IBAction func StartWalk(_ sender: Any)
    {
        if play == true
        {
            play = false

            //Set resetbutton disabled.
            ResetButton.isHidden = true

            //Set new image when play is true
            PlayStop.setImage(UIImage(named: "Stop"), for: .normal)

            //Bool to check if button is stopped (op)
            isStopped = false

            //Checking userpermission to allow map and current location
            if (CLLocationManager.locationServicesEnabled())
            {
                locationManager.requestAlwaysAuthorization()
                locationManager.requestWhenInUseAuthorization()

                //Retrieve current position
                if let userLocation = locationManager.location?.coordinate
                {
                    //Zooming in to current position
                    let viewRegion = MKCoordinateRegion(center: userLocation, latitudinalMeters: 200, longitudinalMeters: 200)
                    mapView.setRegion(viewRegion, animated: false)

                    //Creating a start annotation
                    let annotation = MKPointAnnotation()
                    annotation.title = "Start"
                    annotation.coordinate = userLocation
                    mapView.addAnnotation(annotation)


                }
            }

        }

    }

这是折线的想法:

//Create polyline
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer
    {
        if(overlay is MKPolyline)
        {
            let polyLineRender = MKPolylineRenderer(overlay: overlay)
            polyLineRender.strokeColor = UIColor.blue.withAlphaComponent(1)
            polyLineRender.lineWidth = 3

            return polyLineRender
        }

        return MKPolylineRenderer()
    }

    //Updating location + polylines
    @objc func update()
    {
        //Startposition
        let startLat = locationManager.location?.coordinate.latitude
        let startlong = locationManager.location?.coordinate.longitude
        let startResult = CLLocation(latitude: startLat!, longitude: startlong!)


        //This should be the current user location.
        let stopLat = locationManager.location?.coordinate.latitude
        let stopLong  = locationManager.location?.coordinate.longitude
        let stopResult = CLLocation(latitude: stopLat!, longitude: stopLong!)


        let locations =
        [
            CLLocationCoordinate2D(latitude: startLat!, longitude: startlong!),
            CLLocationCoordinate2D(latitude: stopLat!, longitude: stopLong!)
        ]

            //Draw polyline on the map
            let aPolyLine = MKPolyline(coordinates: locations, count: locations.count)

            //Adding polyline to mapview
            mapView.addOverlay(aPolyLine)

    }

简而言之:

我想让折线从起始位置开始，然后跟随用户走到哪里，直到按下停止按钮。喜欢无时无刻不在追逐那个蓝点。你知道吗？请打我

Answer 1

您是否在您的 ViewController 类上实现了 MKMapViewDelegate 方法？

如果是，您可以从 MapView 访问委托(delegate)，您必须添加 viewDidLoad 函数或任何其他您希望使用坐标的以下代码:

mapView.delegate = self
// Connect all the mappoints using Poly line.

 var points: [CLLocationCoordinate2D] = [CLLocationCoordinate2D]()

  for annotation in annotations {
     points.append(annotation.coordinate)
  }     
  var polyline = MKPolyline(coordinates: &points, count: points.count)
  mapView.addOverlay(polyline)

您可以按照下面的教程进行操作，它非常好:http://rshankar.com/how-to-add-mapview-annotation-and-draw-polyline-in-swift/