C# → 用TreeView实现树菜单
具体方法是：创建一个数据库，设计树图信息表S_Menu，包含NodeId、ParentId、NodeName、Address、Icon字段，其它字段根据实际业务而定，节点名称NodeName将在树型控件的节点上显示，NodeId字段保存节点的唯一标识号，ParentId表示当前节点的父节点号，标识号组成了一个“链表”，记录了树上节点的结构。设计一个Web窗体其上放置TreeView控件，修改其属性Id为tvMenu。
数据结构如下：
CREATE TABLE [dbo].[S_Menu] (
[NodeId] [char] (6) COLLATE Chinese_PRC_CI_AS NULL ,
[ParentId] [char] (6) COLLATE Chinese_PRC_CI_AS NULL ,
[NodeName] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
[Address] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
[Icon] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL
) ON [PRIMARY]
GO
数据库如下：
NodeId ParentId NodeName Address Icon
100000 0 公共查询部 icon_document.gif
100001 100000 人民币日报查询 public/a1.aspx icon_settings.gif
100002 100000 外币日报查询 public/a2.aspx icon_settings.gif
100003 0 分行科技部 icon_document.gif
100004 100003 人民币日报查询 tech/a1.aspx icon_settings.gif
100005 100003 外币日报查询 tech/a2.aspx icon_settings.gif
100006 0 福田支行 icon_document.gif
100007 100006 月存款进度表 a1.aspx icon_settings.gif
100008 100006 月存款走势图 a2.aspx icon_settings.gif
100009 0 罗湖支行 icon_document.gif
100010 100009 月存款进度表 a1.aspx icon_settings.gif
100011 100009 月存款走势图 a2.aspx icon_settings.gif
menu_left.aspx文件如下：
<%@ Register TagPrefix="iewc" Namespace="Microsoft.Web.UI.WebControls" Assembly="Microsoft.Web.UI.WebControls, Version=1.0.2.226, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Page language="c#" Codebehind="menu_Left.aspx.cs" AutoEventWireup="false" Inherits="hzquery.menu.menu_Left" %>
<HTML>
<HEAD>
<title>menu_Left</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio 7.0">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="menu_Left" method="post" runat="server">
<iewc:TreeView id="tvMenu" runat="server"></iewc:TreeView>
</form>
</body>
</HTML>
CodeBehind代码如下：
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using Microsoft.Web.UI.WebControls;
using System.Data.SqlClient;
namespace hzquery.menu
{
/// <summary>
/// menu_Left 的摘要说明。
/// </summary>
public class menu_Left : System.Web.UI.Page
{
protected Microsoft.Web.UI.WebControls.TreeView tvMenu;
SqlConnection Conn;
SqlDataAdapter myCmd;
DataSet ds;
string cmdSelect;
private void Page_Load(object sender, System.EventArgs e)
{
Conn=new SqlConnection(Application["ConnString"].ToString());
CreateDataSet();
InitTree(tvMenu.Nodes,"0");
}
//建立数据集
private DataSet CreateDataSet()
{
cmdSelect="select * from S_Menu";
myCmd=new SqlDataAdapter(cmdSelect,Conn);
ds=new DataSet();
myCmd.Fill(ds,"tree");
return ds;
}
//建树的基本思路是：从根节点开始递归调用显示子树
private void InitTree(TreeNodeCollection Nds,string parentId)
{
DataView dv=new DataView();
TreeNode tmpNd;
string intId;
dv.Table=ds.Tables["tree"];
dv.RowFilter="ParentId="" + parentId + """ ;
foreach(DataRowView drv in dv)
{
tmpNd=new TreeNode();
tmpNd.ID=drv["NodeId"].ToString();
tmpNd.Text=drv["NodeName"].ToString();
tmpNd.ImageUrl="../webimages/"+drv["Icon"].ToString();
tmpNd.NavigateUrl="../"+drv["Address"].ToString();
Nds.Add(tmpNd);
intId=drv["ParentId"].ToString();
InitTree(tmpNd.Nodes,tmpNd.ID);
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
InitializeComponent();
base.OnInit(e);
}
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}
