.Net中实现无限分类的2个例子

 public partial class _Default : System.Web.UI.Page
    {
        BIL bil = new BIL();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                bind_tree("0",null);
            }
        }
        protected void bind_tree(string ChildNode,TreeNode tn)
        {
            DataTable dt = bil.GetByClassPre(ChildNode).Tables[0];

            foreach (DataRow dr in dt.Rows)
            {
                TreeNode Node = new TreeNode();
                if (tn==null)
                {
                    //根
                    Node.Text = dr["ClassName"].ToString();
                    this.TreeView1.Nodes.Add(Node);
                    bind_tree(dr["ClassId"].ToString(), Node);
                }
                else
                {
                    //当前节点的子节点
                    Node.Text = dr["ClassName"].ToString();
                    tn.ChildNodes.Add(Node);
                    bind_tree(dr["ClassId"].ToString(),Node);
                }
            }
        }
    }

protected void bind_droplist(string ChildNode, string tmp)
        {
            DataTable dt = bil.GetByClassPre(ChildNode).Tables[0];

            foreach (DataRow dr in dt.Rows)
            {
                if (dr["ClassPre"].ToString()=="0")
                {
                    //如果是根节点
                    tmp = "";
                    DropDownList1.Items.Add(dr["ClassName"].ToString());
                    bind_droplist(dr["ClassId"].ToString(), tmp + "　");
                }
                else
                {
                    //不是根节点
                    DropDownList1.Items.Add( tmp+"|-" + dr["ClassName"].ToString());
                    bind_droplist(dr["ClassId"].ToString(), tmp + "　");
                }
            }
        }