mapgis线转面

               //GeoPolygon surface = (GeoPolygon)((IGeometry3D)sfcls.GetGeometry(recordSet.CurrentID)).GetBoundary();
                // GeoPolygon surface = (GeoPolygon)((IGeometry3D)recordSet.Geometry).GetBoundary();

                GeoPolygon surface = new GeoPolygon();
                GeoLines pmGeoLines = new GeoLines();       
                pmGeoLines.Append((GeoVarLine)((IGeometry3D)recordSet.Geometry).GetBoundary());
                surface.Append(pmGeoLines);