C# TreeView无限目录树实现方法

#region 绑定客户树
protected void bindTreeView()
{
  TreeView1.Nodes.Clear();
  string userid = Session["UserID"].ToString();
  string sqlwr = new SY_ADMINUSER().GetUserIDListByLoginUser(userid,"CUSTOMERSERVICE",false);
  DataTable dt = Maticsoft.DBUtility.DbHelperOra.Query("Select PARENTID,CUSTOMERID,CUSTOMERSHORT,CUSTOMERSERVICE from CU_CUSTOMER where ISDELETE='0' " + sqlwr + " order by CUSTOMERSHORT ").Tables[0];
  //定义临时树节点
  TreeNode tmpNd;
  //特殊处理
  foreach (DataRow dr in dt.Rows)
  {
    DataRow[] drs = dt.Select("CUSTOMERID='" + dr["PARENTID"] + "'");
    if (drs.Length == 0) //无上级节点
    {
      dr["PARENTID"] = "0";
    }
  }
  dt.AcceptChanges();
  //从DataTable中得到所有父节点为null的DataRow形成的数组
  DataRow[] rows = dt.Select("PARENTID='0'");
  //遍历根节点数组
  foreach (DataRow row in rows)
  {
    tmpNd = new TreeNode();
    //给根节点赋值
    tmpNd.Value = row["CUSTOMERID"].ToString();
    tmpNd.Text = row["CUSTOMERSHORT"].ToString();
    tmpNd.Expanded = true;
    //将节点加入到树中
    TreeView1.Nodes.Add(tmpNd);
    AddTree(dt,TreeView1,tmpNd,row["CUSTOMERID"].ToString());
  }
}
public void AddTree(DataTable dt,TreeView tv,TreeNode pNode,string CUSTOMERID)
{
  DataRow[] rows = dt.Select("PARENTID='" + CUSTOMERID + "'");
  TreeNode tmpNd;
  foreach (DataRow row in rows)
  {
    tmpNd = new TreeNode();
    //给根节点赋值
    tmpNd.Value = row["CUSTOMERID"].ToString();
    tmpNd.Text = row["CUSTOMERSHORT"].ToString();
    tmpNd.Expanded = true;
    pNode.ChildNodes.Add(tmpNd);
    //将节点加入到树中
    //TreeView1.Nodes.Add(pNode);
    AddTree(dt,row["CUSTOMERID"].ToString());
  }
}
#endregion