无法在地图标记中显示来自 Google 方向 JSON 的信息 - iOS Swift 应用

Question

我尝试使用 Google Directions API 获取从我的位置到地图上选定标记的距离和持续时间。我正在使用 Alamofire + SwiftyJSON 来执行 HTTP 请求并解析我返回的 JSON。

我使用这种方法来请求和解析 JSON：

    func fetchDistanceFrom(from: CLLocationCoordinate2D, to: CLLocationCoordinate2D, completionHandler: (String?, String?, NSError?) -> ()) -> ()
{
    let urlString = "https://maps.googleapis.com/maps/api/directions/json?key=\(apiKey)&origin=\(from.latitude),\(from.longitude)&destination=\(to.latitude),\(to.longitude)&mode=walking"

    var parsedDistance : String?
    var parsedDuration : String?

    request(.GET, urlString)
        .responseJSON { (req, res, json, error) in
            if(error != nil) {
                NSLog("Error: \(error)")
            }
            else {
                var json = JSON(json!)
                parsedDistance = json["routes"][0]["legs"][0]["distance"]["text"].stringValue as String!
                parsedDuration = json["routes"][0]["legs"][0]["duration"]["text"].stringValue as String!
                dispatch_async(dispatch_get_main_queue()) {
                    completionHandler(parsedDistance, parsedDuration, error)
                }
            }
    }
}

我在我的 MapView 类中这样使用它：

func mapView(mapView: GMSMapView!, didTapMarker marker: GMSMarker!) -> Bool {
    let selectedMarker = marker as! ExtendedMarker

    dataProvider.fetchDistanceFrom(mapView.myLocation.coordinate, to: marker.position){ (parsedDistance, parsedDuration, error) in

        let busStopDistance = parsedDistance
        let busStopDuration = parsedDuration

            selectedMarker.distance = "Distance: \(busStopDistance!)"
            selectedMarker.duration = "Duration: \(busStopDuration!)"
    }
    return false
}

之后在此方法中显示信息：

    func mapView(mapView: GMSMapView!, markerInfoContents marker: GMSMarker!) -> UIView! {
    let selectedMarker = marker as! ExtendedMarker

    if let infoView = UIView.viewFromNibName("MarkerInfoView") as? MarkerInfoView {

        infoView.nameLabel.text = selectedMarker.name
        infoView.linesTextView.text = selectedMarker.lines
        infoView.distanceLabel.text = selectedMarker.distance
        infoView.durationLabel.text = selectedMarker.duration

        return infoView
    } else {
        return nil
    }
}

但它没有按预期工作，因为我第一次单击地图上的标记时不知何故无法获得距离和时间。它总是在第二次点击标记时出现。看起来我从 Google 获得了 JSON 对象，只是在 MapView 显示标记信息之前没有对其进行解析。

请问有什么办法可以解决这个问题吗？我会非常感谢任何建议。谢谢。

Answer 1

我已经通过在 didTapMarker 方法中强制刷新标记来使其工作，如下所示：

func mapView(mapView: GMSMapView!, didTapMarker marker: GMSMarker!) -> Bool {
    let selectedMarker = marker as! ExtendedMarker

    dataProvider.fetchDistanceFrom(mapView.myLocation.coordinate, to: marker.position){ (parsedDistance, parsedDuration, error) in

        let busStopDistance = parsedDistance
        let busStopDuration = parsedDuration

            selectedMarker.distance = "Distance: \(busStopDistance!)"
            selectedMarker.duration = "Duration: \(busStopDuration!)"

            mapView.selectedMarker = nil;
            mapView.selectedMarker = selectedMarker;
    }
    return false
}

Answer 2

使用 swift 2.0 和 Alamomfire 获取距离 google maps sdk ios：

//get Distance two points
func getDistanceFrom(de: CLLocationCoordinate2D, para: CLLocationCoordinate2D){

    let urlString = "https://maps.googleapis.com/maps/api/directions/json?key=\(GoogleMapsApiKey)&origin=\(de.latitude),\(de.longitude)&destination=\(para.latitude),\(para.longitude)&mode=walking"

    Alamofire.request(.POST, urlString, parameters: nil, encoding: .JSON, headers: nil)

        .responseJSON { (retorno) -> Void in
            //print(retorno.result.value)

            if retorno.result.isSuccess {
                if let km = retorno.result.value?.objectForKey("routes")?[0].objectForKey("legs")?[0].objectForKey("distance") as? NSDictionary{

                    if let km_KM = km.valueForKey("text") as? String {
                        dispatch_async(dispatch_get_main_queue(), { () -> Void in
                            self.LB_DistanciaKM.text = km_KM
                        })
                    }
                }
            }
    }
}

Answer 3

使用 Swift 3 和 Alamofire

func getGoogleMapGeoCodeDurationWithAlamofire(url: String) {
        Alamofire.request(url).responseJSON { response in
            let result = response.result
            if let result = result.value as? Dictionary<String, AnyObject> {
                if let routes = result["routes"] as? [Dictionary<String, AnyObject>] {
                    if let distance = routes[0]["legs"] as? [Dictionary<String, AnyObject>] {
                        print(distance[0]["distance"]?["text"] as! String)
                        print(distance[0]["duration"]?["text"] as! String)

                    }
                }
            }
        }

    }