如何使用swift在googlemaps ios sdk中添加多个折线颜色？

Question

我有一些位置，例如： - a到b点，c到点d。

点a到b应该用红色绘制，点d到c应该用黄色绘制。这一点c和点d将是移动车辆，因此它将是动态的。

目前

 func initializePolylineAnnotation2(_newLocation: CLLocation)
    {
        //self.polyline.strokeColor = UIColor(red:1.00, green:0.84, blue:0.00, alpha:1.0)

        //self.polyline.strokeWidth = 5.0
           var polyline = GMSPolyline()
        let solidRed = GMSStrokeStyle.solidColor(UIColor(red:1.00, green:0.84, blue:0.00, alpha:1.0))
        polyline.spans = [GMSStyleSpan(style: solidRed)]

        polyline.map = self.mapView
        self.updateOverlay(_newLocation,polyline: polyline)
        self.updateCurrentPositionMarker(_newLocation)

    }


func updateOverlay(_ currentPosition: CLLocation,polyline : GMSPolyline)
    {

        self.path.add(currentPosition.coordinate)
        polyline.path = self.path
        if self.DBidArr.contains(self.movingChannel)
        {
            let index = self.DBidArr.index(of: self.movingChannel)

            if index! < self.pathDB.count
            {
                self.pathDB[index!].add(currentPosition.coordinate)
            }
        }

    }