ESRI.ArcGIS.ADF.Web.UI.WebControls.Map mapctrl = (ESRI.ArcGIS.ADF.Web.UI.WebControls.Map) args.Control;
// Get MapFunctionality from the control...
MapFunctionality mapfunc = (MapFunctionality) mapctrl.GetFunctionality(mapctrl.MapResourceManagerInstance.ResourceItems.Count - 1);
MapResourceLocal mapres = (MapResourceLocal) mapfunc.MapResource;
IServerContext sc = mapres.ServerContextInfo.ServerContext;
IMapServer map = mapres.MapServer;
IMapServerObjects mapobj = (IMapServerObjects) map;
IMap fgmap = mapobj.get_Map(map.DefaultMapName);
IFeatureLayer fl = (IFeatureLayer) fgmap.get_Layer(0);
IFeatureClass fc = fl.FeatureClass;