Windows Phone 7 - Jogging Application Part 2

In an earlier blog, I produced a very basic application for Windows Phone 7 that allowed joggers to track their progress of a training session on a Bing Map. The application simply plotted a map polyline whenever there was a change in the device’s location, with the changes in the devices location being raised as events by the GeoCoordinateWatcher class, which is part of the Windows Phone 7 API.

Now although the user’s training session was plotted on the map, with the start and end points being identified with pushpins on the map, the application didn’t indicate to the user the total distance travelled, so to obtain this I decided to use the Route Service, which is one of the Bing Maps Web Services.

Route Service
As the name suggests, the route service is an API used to calculate routes between designated start and end points.

In order to use the Route service, a service reference to http://dev.virtualearth.net/webservices/v1/routeservice/routeservice.svc?wsdl needs to be added to the project.
Please note that currently you are unable to add a service reference from a Windows Phone 7 project within the Visual Studio 2010 release candidate, although this functionality does work correctly within Visual Studio 2010 Express for Windows Phone, so you can simply add the reference there, then reopen the project from within Visual Studio.

Upon adding the reference to the service, the RouteServiceClient becomes available. Now to calculate a route you would typically just pass to the RouteServiceClient the details of the start and end points for your route, now in my case this is still the case, but I also pass in the location details of the jogger’s entire route. This then ensures that the Route Service will use exactly the same route as that used by the jogger.

To pass in the route details to the client, you create an instance of the RouteRequest class. This class has a WayPoints property, which is a collection that holds instances of WayPoint classes, with a WayPoint class simply acting as a container for a single location, represented by longitude and latitude.

Once all of the Way Points have been set, you simply pass the RouteRequest to the CalculateRouteAsync method of the RouteServiceClient. Once the asynchronous call to the web service is complete a RouteResponse is returned, and this details all of the directions of the route (represented as RouteLegs), as well the total distance travelled.

Now although the distance travelled seemed accurate to me, I needed to verify that the route returned by the route service, was identical to each of the locations that I had passed to it. To do this I simply iterated through each of the returned RouteLegs and overlaid them as a new Map Polyline on my Bing Map. Seeing this overlay on the map verified that the data returned was as expected.

 private void CalculateRoute()
 {
   RouteRequest routeRequest = new RouteRequest();
   ApplicationIdCredentialsProvider mapCredentials = (ApplicationIdCredentialsProvider)Application.Current.Resources["MapCredentials"];
   string credentialID = mapCredentials.ApplicationId; 
   routeRequest.Credentials = new Credentials() { ApplicationId = credentialID };
   Waypoint[] waypoints = new Waypoint[_joggingSession.Locations.Count];
   for (int i = 0; i < waypoints.Length; i++)
   {
     Waypoint waypoint = new Waypoint();
     waypoint.Location = new Location(_joggingSession.Locations[i].Latitude, _joggingSession.Locations[i].Longitude);
     waypoints[i] = waypoint;
   }

   routeRequest.Waypoints = waypoints;
   RoutingService.RouteServiceClient routeService = new RouteServiceClient("BasicHttpBinding_IRouteService");
   routeService.CalculateRouteCompleted += new EventHandler(routeService_CalculateRouteCompleted);
   routeRequest.Options = new RouteOptions();
   routeRequest.Options.Mode = TravelMode.Walking;
   routeRequest.UserProfile = new UserProfile() { DistanceUnit = DistanceUnit.Mile };
   routeService.CalculateRouteAsync(routeRequest);
 }

 void routeService_CalculateRouteCompleted(object sender, CalculateRouteCompletedEventArgs e)
 {
   RouteResponse routeResponse = e.Result;
   _joggingSession.DistanceTravelled = routeResponse.Result.Summary.Distance;
   DistanceTravelled.Text =  _joggingSession.DistanceTravelled.ToString("000.00") + " miles";
   //verfiy distance travelled by overlaying the returned route on top of the real time route.
   foreach (RouteLeg routeLeg in routeResponse.Result.Legs)
   {
     _routePolyLine.Locations.Add(routeLeg.ActualStart);
     _routePolyLine.Locations.Add(routeLeg.ActualEnd);
   }
 }