How to change the color of a MGLPolyline?

问题

How can I change the color of an MGLPolyline? I had looked here but the answer did not work. I also tried some other code but it was too dependant on apple maps. So how can I change the color of the line and preferably be able to edit other aspects of the line as well? Bellow is where I believe in the code I should be doing these edits but I am not 100%.

        @objc func useButtonTap(_ sender: UIGestureRecognizer) {
        print("use tap button pressed")
        startButton.backgroundColor = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 0.9)
        useTrackButton.backgroundColor = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 0.9)

        locationManager?.stopUpdatingLocation()

        print(locationList, "<-- location manager array in use button")
        if locationList == [] {
            print("nothing was tracked")
        } else {

            var mapCoordinates: [CLLocationCoordinate2D] = []

            for locationT in locationList {
                print(locationT, "<-- locationT")
                print(locationT.coordinate.latitude, "<-- latitude")
                print(locationT.coordinate.longitude, "<-- longitude")

                let locationLatitude = locationT.coordinate.latitude
                let locationLongitude = locationT.coordinate.longitude

                print(locationLatitude, "lat")
                print(locationLongitude, " long")
                let newCoord = CLLocationCoordinate2D(latitude: locationLatitude, longitude: locationLongitude) // - (0.0001/2)
                print(newCoord, "<-- new coord")
                mapCoordinates.append(newCoord)//+ 0.0001

            }

            polyline = MGLPolyline(coordinates: mapCoordinates, count: UInt(mapCoordinates.count))
//            toCome = polyline
//            mapView.add(polyline)

            mapView.addAnnotation(polyline) //used to be jsut .add, changed in order to try anwser for color chaning of polyline

        }
    }

回答1:

You can set the color and width of a polyline in MKMapViewDelegate function only. Check example below.

  public func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
      let polyLine = overlay as? MKPolyline
      let renderer = MKPolylineRenderer(overlay: overlay)
      renderer.lineWidth = 2.5
      renderer.strokeColor = UIColor(red: 47/255, green: 62/255, blue: 158/255, alpha: 1.0)
      return renderer
  }

回答2:

You have to make mapView.delegate = self

Then implement this method:

func mapView(_ mapView: MGLMapView, strokeColorForShapeAnnotation annotation: MGLShape) -> UIColor {

  return .blue
}

来源：https://stackoverflow.com/questions/54566855/how-to-change-the-color-of-a-mglpolyline

标签

ios

swift

mglmapview