private void Initialize()
{
// Create a new ArcGISVectorTiledLayer with the navigation service Url
_vectorTiledLayer = new ArcGISVectorTiledLayer(new Uri(_navigationUrl));
// Create new Map with basemap
Map myMap = new Map(new Basemap(_vectorTiledLayer));
// Set titles as a items source
vectorLayersChooser.ItemsSource = _vectorLayerNames;
// Assign the map to the MapView
MyMapView.Map = myMap;
}