C # generate an unlimited menu

An unlimited menu is used in a recently developed project, so this code is pasted for research. The development environment is VS2008 + SQL 2000.

First, the code for creating a database table is as follows:

Database Table code of the infinite level tree If exists (select * from dbo. sysobjects where id = object_id (N [dbo]. [work_sysmenu]) and OBJECTPROPERTY (id, NIsUserTable) = 1)
Drop table [dbo]. [work_sysmenu]
GO

Create table [dbo]. [work_sysmenu] (
[Flowid] [int] IDENTITY (1, 1) not null,
[Menu_title] [varchar] (100) COLLATE Chinese_PRC_CI_AS NULL,
[Menu _value] [varchar] (100) COLLATE Chinese_PRC_CI_AS NULL,
[Menu_url] [varchar] (500) COLLATE Chinese_PRC_CI_AS NULL,
[Menu_parent] [int] NULL,
[Menu_role] [varchar] (200) COLLATE Chinese_PRC_CI_AS NULL,
[Menu_meno] [text] COLLATE Chinese_PRC_CI_AS NULL,
[Isvalid] [int] NULL,
[Menu_order]