using System; using System.Collections; using System.Linq; using System.Web; using System.Web.Services; using System.Web.Services.Protocols; using System.Xml.Linq; //访问数据库命名空间 using System.Data; using System.Data.SqlClient; //访问web.config命名空间 using System.Web.Configuration; //导入ScriptServiceAttribute类的命名空间 using System.Web.Script.Services; //返回CascadingDropDownNameValue数组所需的命名空间 using AjaxControlToolkit; using System.Collections.Generic; using System.Collections.Specialized;