Autodesk.Gis.Map.ImportExport.Importer myimporter = null;
Autodesk.Gis.Map.MapApplication mapapp = Autodesk.Gis.Map.HostMapApplicationServices.Application;
myimporter = mapapp.Importer;
myimporter.Init("SHP", file);
myimporter.ImportPolygonsAsClosedPolylines = true;
myimporter.Import(true);