private void routeTask_SolveCompleted(object sender, RouteEventArgs e)
{
GraphicsLayer routeLayer = MyMap.Layers["MyRouteGraphicsLayer"] as GraphicsLayer;
RouteResult routeResult = e.RouteResults[0];
routeResult.Route.Symbol = LayoutRoot.Resources["RouteSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
routeLayer.Graphics.Clear();
Graphic lastRoute = routeResult.Route;
routeLayer.Graphics.Add(lastRoute);
}