Question

我想在我的谷歌地图应用程序上有一条路线，我使用此代码 - ＆gt;

   func getPolylineRoute(from source: CLLocationCoordinate2D, to destination: CLLocationCoordinate2D){

    let config = URLSessionConfiguration.default
    let session = URLSession(configuration: config)

    let url = URL(string: "https://maps.googleapis.com/maps/api/directions/json?origin=\(source.latitude),\(source.longitude)&destination=\(destination.latitude),\(destination.longitude)&sensor=false&mode=walking&key=**MY KEY**")!


    let task = session.dataTask(with: url, completionHandler: {
        (data, response, error) in
        if error != nil {
            print(error!.localizedDescription)
        }else{
            do {
                if let json : [String:Any] = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any]{

                    let routes = json["routes"] as? [Any]
                    let overViewPolyLine = routes?[0] as?[String:Any]
                    let polyString = overViewPolyLine?["points"] as?String

                    //Call this method to draw path on map
                    self.showPath(polyStr: polyString!)
                }

            }catch{
                print("error in JSONSerialization")
            }
        }
    })
    task.resume()
}

func showPath(polyStr :String){
    let path = GMSPath(fromEncodedPath: polyStr)
    let polyline = GMSPolyline(path: path)
    polyline.strokeWidth = 3.0
    polyline.map = googleMapsView // Your map view
}

我迷恋这一行 - ＆gt;

enter image description here

我该怎么做才能解决这个问题？

Answer 1

如果在索引0处出现超出范围的异常，则该数组为空。

使用可选绑定来安全地打开选项。

if let json = try JSONSerialization.jsonObject(with: data!) as? [String:Any],
   let routes = json["routes"] as? [[String:Any]], // don't use [Any] if the type is more specific
   let overViewPolyLine = routes.first,
   let polyString = overViewPolyLine["points"] as? String {

       //Call this method to draw path on map
       self.showPath(polyStr: polyString)
}

致命错误：路线中的指数超出范围（谷歌地图）

1 个答案: