Question

我试图在两点之间绘制路线但是不能这样做beacuese在我的polypoints中有nill值。我就是这样做的：

解析JSON：

if let json : [String:Any] = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any]{

                        if let routes = json["routes"] as? [Any]{
                            if let overview_polyline = routes[0] as?[String:Any]{
                                print("overview_polyline\(overview_polyline)")// Getting values till here
                                if let polyString = overview_polyline["points"] as? String{

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

                            }
                        }
                    }

直到polytring我得到了值但没有得到这行代码if let polyString = overview_polyline["points"] as? String的任何值。知道为什么polyString nil ？

我已经通过此链接来清除仍然无法实现它的概念。 unexpectedly found nil while unwrapping an Optional value

Answer 1

我通过将上面的代码修改为此代码来实现此目的。因此，要解析谷歌api并在地图上创建折线，您可以使用此代码，用swift 3编写。

if let json : [String:Any] = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any]{
      let routes = json["routes"] as! NSArray;
      print(routes)
      self.mapView.clear()
      OperationQueue.main.addOperation({
          for route in routes {
                let routeOverviewPolyline:NSDictionary = (route as! NSDictionary).value(forKey: "overview_polyline") as! NSDictionary
                let points = routeOverviewPolyline.object(forKey: "points")
                let path = GMSPath.init(fromEncodedPath: points! as! String)
                let polyline = GMSPolyline.init(path: path)
                polyline.strokeWidth = 3
                polyline.map = self.mapView
           }
       })
}

无法绘制折线谷歌地图：Swift 3

1 个答案: