VC+MO+SDE

我用VC++6.0,Mo2.2,SDEforOracle8.3
 CMoLayers layers(m_map.GetLayers());
 CMoDataConnection conn;
 if (!conn.CreateDispatch(TEXT("MapObjects2.DataConnection")))
 {
  MessageBox("MO的DataConnection对象不能创建！");
  return;
               }
 conn.SetServer("SDE83:"+m_server);
 conn.SetDatabase(m_database);
 conn.SetUser(m_user);
 conn.SetPassword(m_password);
 if (!conn.Connect())
  return;
               CMoMapLayer layer;
  if (!layer.CreateDispatch(TEXT("MapObjects2.MapLayer")))
  throw "unable to create MapObjects2.MapLayer";
 
 CMoGeoDataset geoDataset(conn.FindGeoDataset(m_table));//这句出错
  好象建立不了geoDataset为NULL                    m_table=SDE.road.Features.Lines
 layer.SetGeoDataset(geoDataset);
 layers.Add(layer);
 m_map.Refresh();