GeometryCollection如何構造一個環

IGeometryPtr   ipGeometry1;
     IGeometryPtr   ipGeometry2;
            IGeometryPtr   ipGeometry3;
   
  

     long           lOID1,lOID2;
             ipFeature1->get_Shape(&ipGeometry1);
             ipFeature1->get_OID(&lOID1);
    ipFeature2->get_Shape(&ipGeometry2);
             ipFeature2->get_OID(&lOID2);
            
             IGeometryCollectionPtr ipGeometryCollection(CLSID_Polygon);
             IGeometryCollectionPtr ipGeometryCollection1;
    IGeometryCollectionPtr ipGeometryCollection2;
             ipGeometryCollection1=ipGeometry1;
             ipGeometryCollection2=ipGeometry2;
            
   
             hr= ipGeometryCollection->AddGeometryCollection(ipGeometryCollection1);
              if(FAILED(hr))
       return ;
             hr= ipGeometryCollection->AddGeometryCollection(ipGeometryCollection2);
              if(FAILED(hr))
       return ;
     ipGeometryCollection->QueryInterface(IID_IGeometry,(void **)&ipGeometry3);
              if(FAILED(hr))
       return ;
   
             ITopologicalOperatorPtr ipTopogicalOperator;
             ipTopogicalOperator=ipGeometry3;
             ipTopogicalOperator->Simplify();
             IFeaturePtr ipFeature3(CLSID_Feature);
             ipPolygonFeatureClass->CreateFeature(&ipFeature3);
            
             ipFeature3->putref_Shape(ipGeometry3);
             hr= ipFeature3->Store();
             if(FAILED(hr))
       return ;