ListBox 控件允许用户从预定义的列表中选择一个或多个项。它与 DropDownList 控件的不同之处在于，它不但可以一次显示多个项，而且（可选）还允许用户选择多个项。
一、属性
| 属性 | 值 | 作用 |
|---|---|---|
| SelectionMode | Single|Multiple | 列表选择模式：单选|多选 |
| Selected | False|True | 是否为选中状态 |
二、示例
ListBox.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ListBox.aspx.cs" Inherits="WebControls_ListBox" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<style type="text/css">
.style1
{
width: 293px;
}
.style2
{
width: 233px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<h5>1,单选列表框</h5>
省份：<asp:ListBox ID="lstProv" runat="server">
<asp:ListItem>山东</asp:ListItem>
<asp:ListItem Selected="True">河北</asp:ListItem>
<asp:ListItem>内蒙</asp:ListItem>
<asp:ListItem>安徽</asp:ListItem>
</asp:ListBox>
<br />
<asp:Button ID="btnSubmit" runat="server" Text="提交" onclick="btnSubmit_Click" />
<hr />
你选择的为：<asp:Label ID="lblState" runat="server"></asp:Label>
<hr />
<h5>
2,多选列表框</h5>
省份：<asp:ListBox ID="lstProv2" runat="server" SelectionMode="Multiple">
<asp:ListItem>山东</asp:ListItem>
<asp:ListItem Selected="True">河北</asp:ListItem>
<asp:ListItem>内蒙</asp:ListItem>
<asp:ListItem>安徽</asp:ListItem>
</asp:ListBox>
提示：Ctrl+单击<br />
<asp:Button ID="btnSubmit2" runat="server" Text="提交"
onclick="btnSubmit2_Click" />
<hr />
你选择的为：<asp:Label ID="lblState2" runat="server"></asp:Label>
</div>
</form>
</body>
</html>
</div>
ListBox.aspx.cs
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class WebControls_ListBox : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnSubmit_Click(object sender, EventArgs e)
{
lblState.Text = lstProv.SelectedValue;
}
protected void btnSubmit2_Click(object sender, EventArgs e)
{
string str = string.Empty;
for (int i = 0; i < lstProv2.Items.Count; i++)
{
if (lstProv2.Items[i].Selected == true)
{
str = string.Format("{0}{1},",str,lstProv2.Items[i].Value);
}
}
str = str.Substring(0, str.Length - 1); //去掉最后一个“,”
lblState2.Text = str;
}
}
</div>