获得ETA ios - 完成处理程序 - 迅捷

Question

我是IOS编码和使用swift的新手 我试图计算两个不同点之间的ETA。当我将地址转换为坐标时，我将它们存储在全局变量中。问题是，由于该值是在完成处理程序中设置的，当我进行调用以计算ETA时，尚未设置变量。什么是获得相同结果的另一种方式。

sourceCoords: CLLocationCoordinate2D?
destCoords: CLLocationCoordinate2D?    
func getETA()



 {
        var locationManager:CLLocationManager = CLLocationManager();
        locationManager.requestAlwaysAuthorization();

        var authorizationStatus:CLAuthorizationStatus = CLLocationManager.authorizationStatus();
        if(authorizationStatus == CLAuthorizationStatus.Authorized ||
        authorizationStatus == CLAuthorizationStatus.AuthorizedWhenInUse)
        {

            let geoCoder = CLGeocoder()


            let sourceAddress =
            [kABPersonAddressStreetKey as NSString: "1 Stockton St",
                kABPersonAddressCityKey: "San Francisco",
                kABPersonAddressStateKey: "California",
                kABPersonAddressZIPKey: "94108"]

            //get coordinates

            geoCoder.geocodeAddressDictionary(sourceAddress, completionHandler:
                {
                    (placemarks: [AnyObject]!, error: NSError!) in

                    if error != nil {

                        println("Geocode failed with error: \(error.localizedDescription)")

                    } else if placemarks.count > 0 {
                        let placemark = placemarks[0] as CLPlacemark
                        let location = placemark.location
                        self.sourceCoords = location.coordinate
                }
            });



            //var requestSource = MKMapItem.mapItemForCurrentLocation();

            let addressDict =
            [kABPersonAddressStreetKey as NSString: "2125 Chestnut St",
                kABPersonAddressCityKey: "San Francisco",
                kABPersonAddressStateKey: "California",
                kABPersonAddressZIPKey: "94123"]



            //get coordinates

            geoCoder.geocodeAddressDictionary(addressDict, completionHandler:
                {
                    (placemarks: [AnyObject]!, error: NSError!) in

                    if error != nil {

                        println("Geocode failed with error: \(error.localizedDescription)")

                    } else if placemarks.count > 0 {
                        let placemark = placemarks[0] as CLPlacemark
                        let location = placemark.location
                        self.destCoords = location.coordinate
                    }
            });

            let placeSource = MKPlacemark(coordinate: sourceCoords!,
                addressDictionary: sourceAddress)

            var requestSource = MKMapItem(placemark: placeSource);

            println(placeSource.location.coordinate.latitude)


            let place = MKPlacemark(coordinate: destCoords!,
                addressDictionary: addressDict)

            var requestDestination = MKMapItem(placemark: place);
            println(place.location.coordinate.latitude)


            var request:MKDirectionsRequest = MKDirectionsRequest();
            request.setSource(requestSource);
            request.setDestination(requestDestination);
            request.transportType = MKDirectionsTransportType.Automobile;
            request.requestsAlternateRoutes = false;


            var directions:MKDirections = MKDirections(request: request)
            directions.calculateDirectionsWithCompletionHandler({
                (response: MKDirectionsResponse!, error: NSError?) in
                if error != nil{
                    println("Error")
                }
                if response != nil{
                    var mkRoute:MKRoute = response.routes.last as MKRoute;
                    println(mkRoute.expectedTravelTime)
                    println(mkRoute.distance)
                    for step in mkRoute.steps
                    {
                         println(step.instructions);
                    }


                }
                else{
                    println("No response")
                }
                println(error?.description)
            })


        }