IEnvelopePtr ipEnv ;
hr = m_ipMapCtrl ->TrackRectangle(& ipEnv);
IPointPtr ipPointUL ;
IPointPtr ipPointUR ;
IPointPtr ipPointLL ;
IPointPtr ipPointLR ;
ipEnv->get_UpperLeft (&ipPointUL);
ipEnv->get_UpperRight (&ipPointUR);
ipEnv->get_LowerLeft (&ipPointLL);
ipEnv->get_LowerRight (&ipPointLR);
IPointCollectionPtr ipPointCollection (CLSID_Polygon);
ipPointCollection->AddPoint (ipPointUL);
ipPointCollection->AddPoint (ipPointLL);
ipPointCollection->AddPoint (ipPointLR);
ipPointCollection->AddPoint (ipPointUR);
ipGeo=ipPointCollection ;