Win RT windows phone 8.1 MapControl：MapRouteFinder.GetDrivingRouteAsync返回某些引脚的InvaldiCredentials状态

Question

我有同样的问题，例如This question，但它仅针对某些方向而不是所有方向。

MapPB.IsIndeterminate = true;
    MapPB.Visibility = Visibility.Visible;
    Geopoint destGeopoint = new Geopoint(new BasicGeoposition() { Latitude = Convert.ToDouble(location.Latitude), Longitude = Convert.ToDouble(location.Longitude) });

                             MapRouteFinderResult routeResult = await MapRouteFinder.GetDrivingRouteAsync(MyGeopoint, destGeopoint, MapRouteOptimization.Distance, MapRouteRestrictions.None);

                             if (routeResult.Status == MapRouteFinderStatus.Success)
                             {
                                 // Use the route to initialize a MapRouteView.
                                 MapRouteView viewOfRoute = new MapRouteView(routeResult.Route);
                                 viewOfRoute.RouteColor = App.ApplicationThemeColor;
                                 viewOfRoute.OutlineColor = App.ApplicationThemeColor;

                                 // Add the new MapRouteView to the Routes collection
                                 // of the MapControl.
                                 MapControl1.Routes.Clear();
                                 MapControl1.Routes.Add(viewOfRoute);

                                 // Fit the MapControl to the route.
                                 await MapControl1.TrySetViewBoundsAsync(
                                     routeResult.Route.BoundingBox,
                                     null,
                                     Windows.UI.Xaml.Controls.Maps.MapAnimationKind.None);
                             } 

                         MapPB.IsIndeterminate = false;
                         MapPB.Visibility = Visibility.Collapsed;

在上面的代码中，routeResult.Status返回InvalidCredentials，但仅限于某些点，而不是所有点。