由于网址为“ found nil”,无法从GoogleMaps获得路线

时间:2019-06-14 14:57:00

标签: swift xcode google-maps maps directions

我在这个主题中进行了搜索,发现了一些我试图在项目中实现的代码,但这无法正常工作!

那么,我想实现什么? 我想在用户界面中有一个按钮,当用户点击按钮时,该应用会在GoogleMap上显示指向特定地点的路线。但是我的函数在URL上崩溃了。

这是我的代码:

func draw(src: CLLocationCoordinate2D, dst: CLLocationCoordinate2D){

    let urlString = "https://maps.googleapis.com/maps/api/directions/json?origin=\(src)&destination=\(dst)&sensor=false&mode=driving&key=**API_KEY**" <- // Here I place API-Key

    let url = URL(string: urlString)  // Here is the crash!

    URLSession.shared.dataTask(with: url!, completionHandler: {
        (data, response, error) in
        if(error != nil){
            print("error")
        }else{
            do{
                let json = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String : AnyObject]
                let routes = json["routes"] as! NSArray
                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

                        let bounds = GMSCoordinateBounds(path: path!)
                        self.mapView!.animate(with: GMSCameraUpdate.fit(bounds, withPadding: 30.0))

                        polyline.map = self.mapView

                    }
                })
            }catch let error as NSError{
                print("error:\(error)")
            }
        }
    }).resume()
}

我不知道问题可能出在API密钥上,还是还有其他问题。我读到空格等可能会导致此问题,但我找不到问题所在!

错误消息:

Fatal error: Unexpectedly found nil while unwrapping an Optional value
2019-06-14 16:50:45 Fatal error: Unexpectedly found nil while unwrapping an Optional value

1 个答案:

答案 0 :(得分:0)

您直接使用<figure class="media-container aspect-ratio-16x9"> <img src="https://picsum.photos/id/1011/500/500" alt="Photo"/> <figcaption>This is a 16x9 image with a caption</figcaption> </figure>错误地创建了urlString,因为您必须使用其属性CLLocationCoordinate2D / latitude

longitude

应该是

let urlString = "https://maps.googleapis.com/maps/api/directions/json?origin=\(src)&destination=\(dst)&sensor=false&mode=driving&key=**API_KEY**" <- // Here I place API-Key

另外,最好避免使用let urlString = "https://maps.googleapis.com/maps/api/directions/json?origin=\(src.latitude),\(src.longitude)&destination=\(dst.latitude),\(dst.longitude)&sensor=false&mode=driving&key=**API_KEY**" <- // Here I place API-Key

!