public class ImageServiceLayer : BasicRasterLayer, ArcGIS.Desktop.Core.IMetadataInfo, IMetadataSource, ITableDefinitionQueries, System.ComponentModel.INotifyPropertyChanged  

ImageServiceLayer isLayer = null;
string url =
@"http://imagery.arcgisonline.com/arcgis/services/LandsatGLS/GLS2010_Enhanced/ImageServer";
await QueuedTask.Run(() =>
{
  // Create an image service layer using the url for an image service.
  isLayer = LayerFactory.Instance.CreateLayer(new Uri(url), aMap) as ImageServiceLayer;
});