DropDownList中绑定树形结构，在线求解答.解决方案

DropDownList中绑定树形结构，在线求解答....
数据库表图
要显示的结果图

C# code

 private void InitDepartDropDown()        {            CustomerControlInfo info;            this.Items.Clear();            this.Items.Add(new ListItem("请选择成员", "0"));            int OwnerUserId = GetOwnerUserID();            ArrayList al = CustomerControlController.GetUCPBerInfoDeptName(OwnerUserId);            if (al.Count > 0)            {                for (int i = 0; i < al.Count; i++)                {                     info = (CustomerControlInfo)al[i];                    int UserId = info.UserId;                    int ParentDept = info.ParentDept;                    string DeptName = info.DeptName;                    if (ParentDept>0)                        {                            DeptName = "**|-" + DeptName;                        }                        else                        {                            DeptName = "|--" + DeptName;                        }                    this.Items.Add(new ListItem(DeptName, UserId.ToString()));                }            }

C# code

 /// <summary>        /// lcl版把一个无限循环数据表绑定数据到一个DropDownList下拉列中，并分层显示        /// </summary>        /// <param name="DropDownList">绑定的控件</param>        /// <param name="dt">需要的dt</param>        /// <param name="firstfather_id">第一项的父ID值</param>        /// <param name="childid">子ID字段名</param>        /// <param name="father_id">父ID字段名</param>        /// <param name="name">显示字段名</param>        /// <param name="needlayer">显示的层数,为负值则不限</param>        /// <param name="firstnull">为定值""</param>        public static void BindDropDownList2(System.Web.UI.WebControls.DropDownList DropDownList, System.Data.DataTable dt, string firstfather_id, string childid, string father_id, string name, int needlayer, string firstnull)        {            if (needlayer > 0 || needlayer < 0)            {                System.Data.DataRow[] drs = dt.Select(father_id + "=" + firstfather_id);                for (int i = 0; i < drs.Length; i++)                {                    DropDownList.Items.Add(new System.Web.UI.WebControls.ListItem(firstnull + drs[i][name].ToString(), drs[i][childid].ToString()));                    string firstnull1 = "";                    if (firstnull.IndexOf("|--") >= 0)                    {                        firstnull1 = "　　" + firstnull;                    }                    else                    {                        firstnull1 = "　|--";                    }                    BindDropDownList2(DropDownList, dt, drs[i][childid].ToString(), childid, father_id, name, needlayer - 1, firstnull1);                }            }        }
[解决办法]
[code=C#][/code]
这是我原来写的一个，其中只允许有一个顶级结点（如果你有多个并列的顶级结点，不妨把他们归入一个顶级结点下面），顶级结点的父节点id默认为空
       /// <summary>
       /// 初始化树接点
       /// </summary>
       protected void initTreeNode()
       {
           conn = new OracleConnection(OraDataConfig.getConnString());
           conn.Open();

           OracleDataAdapter adapter = new OracleDataAdapter("select DEPARTMENT_ID,department_code,PARENT_DEPT_ID from t_department order by DEPARTMENT_ID asc ", conn);
           ds = new DataSet();
           adapter.Fill(ds);
           adapter.Dispose();
           addTree(null, null);
           conn.Close();
       } 
 

       /// <summary>
       /// 递归绑定树节点
       /// </summary>
       /// <param name="parentId">父节点编号</param>
       /// <param name="parentnode">父节点</param>
       protected void addTree(string parentId, TreeNode parentnode)
       {
           for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
           {
               if (parentId == ds.Tables[0].Rows[i][2].ToString().Trim() || parentId == null)
               {
                   TreeNode node = new TreeNode(ds.Tables[0].Rows[i][1].ToString().Trim(),
                       ds.Tables[0].Rows[i][0].ToString().Trim(), string.Empty,
                       string.Format("DeptInfoMain.aspx?deptID={0}", ds.Tables[0].Rows[i][0].ToString().Trim()),
                       string.Format("DeptInfo"));

                   addTree(ds.Tables[0].Rows[i][0].ToString().Trim(), node);
                   if (parentnode == null)
                   {
                       trvDeptInfo.Nodes.Add(node);
                       break;
                   }
                   else
                   {
                       parentnode.ChildNodes.Add(node);
                   }
               }
           }
       }
[解决办法]
DECLARE @t_Level TABLE(ID char(3),Level int,Sort varchar(8000))  
DECLARE @Level int 
SET @Level=0  
INSERT @t_Level SELECT ID,@Level,ID  
FROM sssss  
WHERE PID = 0 
WHILE @@ROWCOUNT>0  
BEGIN  
   SET @Level=@Level+1  
   INSERT @t_Level SELECT a.ID,@Level, b.ID 
   FROM sssss a,@t_Level b  
   WHERE a.PID=b.ID  
       AND b.Level=@Level-1  
END  
   
SELECT a.id,a.pid, SPACE(b.Level*2)+'    |--'+a.Name,b.sort  
FROM sssss a,@t_Level b  
WHERE a.ID=b.ID  
ORDER BY b.Sort,a.id
[解决办法]
 public class DDLDepartment : DropDownList
   {
       public DDLDepartment()
       {
           bind(this, 0);
           this.Items.Insert(0, new ListItem("==请选择==", ""));
       }
       public void bind(DropDownList ddlDepartment, int parent)
       {
           IList<Department> deptlist = DepartmentBLL.SelectChild(parent);
           foreach (Department dept in deptlist)
           {
               string text = new string('　', dept.Depth - 1);
               text += "└" + dept.DeptName;
               ddlDepartment.Items.Add(new ListItem(text, dept.DeptId.ToString()));
               bind(this, dept.DeptNo);
           }
          
       }
       public bool Blank
       {
           set
           {
               if (value == false) this.Items.RemoveAt(0);
           }
          
       }
   }