前台只需要放一个 treeview控件就行

后台

 

 protected void Page_Load(object sender, EventArgs e)
    {
         if (!IsPostBack)
            bindTree();
    }
    private void bindTree()
    {
        DataTable dt = this.GetTreeData();
        this.FillNode(dt, null);
    }
    private void FillNode(DataTable dt, TreeNode node)
    {
        DataView dv = new DataView(dt);
        if (node == null)    //根结点
        {
            dv.RowFilter = "parentid='0'";  //筛选到根结点的所有子节点
        }
        else  //不是根结点
        {
            dv.RowFilter = "parentid='" + node.Value + "'";   //筛选对应节点的所有子节点
        }
        foreach (DataRowView drv in dv)   //遍历填充节点的所有子节点,如果传入的节点node为叶子节点,遍历要退出,不再进行递归
        {
            TreeNode no = new TreeNode(drv["menuname"].ToString(), drv["menuid"].ToString());
            FillNode(dt, no);  //填充no节点的子节点
            if (node == null)
            {
                this.TreeView1.Nodes.Add(no);
            }
            else
            {
                node.ChildNodes.Add(no);
            }
        }       
    }
    private DataTable GetTreeData()
    {
        string strcnn = ConfigurationManager.ConnectionStrings["treecnn"].ConnectionString;
        using (SqlConnection sqlcnn = new SqlConnection(strcnn))
        {
            SqlCommand sqlcmm = sqlcnn.CreateCommand();
            sqlcmm.CommandText = "select * from MenuTree order by parentid,menuorder";
            SqlDataAdapter da = new SqlDataAdapter(sqlcmm);
            DataSet ds = new DataSet();
            da.Fill(ds);
            return ds.Tables[0];
        }
    }