如何从列表框中获取选项组

Question

我需要列表框中的选项组以及选项组中的其他列表。

需要建筑物作为选项组，并且在其中需要服务作为选项。
如图所示的示例

Option Group

在这里，我需要管理员作为选项组的建筑物名称（ ），并保持服务选项的建筑物名称（）。

代码如下所示：-

var en = new HorizonEntities();
        //Service for options
        var serviceStreams = (from x in en.ServiceStreams
                              where x.IsActive == true
                              select x).OrderBy(a => a.ServiceStreamName).ToList();            

        var clientSiteId = Guid.Parse(cbo_Sites.SelectedItem.Value);

        //client site buildings as option group...
        var clientSiteBuildings = (from x in en.ClientSiteBuildings
                                   where x.ClientSiteId == clientSiteId
                                   select x).OrderBy(a => a.ClientSiteBuildingName).ToList();

        cbo_ServiceStream.Items.Clear();
        foreach (ClientSiteBuilding clientSiteBuilding in clientSiteBuildings)
        {
            ListItem item = new ListItem();
            //item.Attributes["OptionGroup"] = clientSiteBuilding.ClientSiteBuildingName;
            //item.Text = clientSiteBuilding.ClientSiteBuildingName;
            //cbo_ServiceStream.Items.Add(item);
            item.Attributes["OptionGroup"] = clientSiteBuilding.ClientSiteBuildingName;
            item.Text = clientSiteBuilding.ClientSiteBuildingName;
            cbo_ServiceStream.Items.Add(item);

            cbo_ServiceStream.Items.Add(new ListItem(clientSiteBuilding.ClientSiteBuildingName, clientSiteBuilding.ClientSiteBuildingId.ToString()));
            foreach (ServiceStream serviceStream in serviceStreams)
            {
                cbo_ServiceStream.Items.Insert(0, new ListItem(serviceStream.ServiceStreamName, serviceStream.ServiceStreamId.ToString()));
            }                
        }

cbo_ServiceStream 是列表框适配器， clientSiteBuildings 是选项组的构建要求，而选项组的 serviceStreams 。