.aspx代码例如以下：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Sample 3-06.aspx.cs" Inherits="Sample_3_6" %>
<!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>
<link href="StyleSheet.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<div id="mydiv">
<h2>CheckBox应用</h2>
<%--程序1--%>
<div>
<asp:CheckBox ID="CheckBox1" runat="server" Text ="我是AutoPostBack"
AutoPostBack="true" oncheckedchanged="CheckBox1_CheckedChanged" />
<asp:TextBox ID="txt_1" runat="server"></asp:TextBox>
</div>
<hr />
<%--程序2--%>
<div id="div_chklist" runat="server" >
<p>请选择你的爱好：</p>
<asp:CheckBox ID="CheckBox2" runat="server" Text ="逛街" Width="100px" />
<asp:CheckBox ID="CheckBox3" runat="server" Text ="喝茶" Width="100px" />
<asp:CheckBox ID="CheckBox4" runat="server" Text ="唱歌" Width="100px" />
<asp:CheckBox ID="CheckBox5" runat="server" Text ="购物" Width="100px" />
<asp:CheckBox ID="CheckBox6" runat="server" Text ="看电影" Width="100px" />
<asp:CheckBox ID="CheckBox7" runat="server" Text ="看书" Width="100px" />
<asp:CheckBox ID="CheckBox8" runat="server" Text ="旅游" Width="100px" />
<asp:CheckBox ID="CheckBox9" runat="server" Text ="听音乐" Width="100px" />
<asp:CheckBox ID="CheckBox10" runat="server" Text ="爬山" Width="100px" />
<asp:CheckBox ID="CheckBox11" runat="server" Text ="玩游戏" Width="100px" />
<asp:CheckBox ID="CheckBox12" runat="server" Text ="看综艺节目" Width="100px" />
<asp:CheckBox ID="CheckBox13" runat="server" Text ="学ASP.NET" Width="100px" />
<br /><br />
<asp:Button ID="btn_submit" runat="server" Text="提交" Height="29px"
Width="78px" onclick="btn_submit_Click" />
<br /><br />
您选择的是：<asp:TextBox ID="TextBox1" runat="server" Height="56px"
Width="310px" TextMode="MultiLine"></asp:TextBox>
</div>
<hr />
<div style="text-align:center; padding:10px; ">
<asp:Button ID="Button1" runat="server" Text="foreach循环语句应用于数组代码演示样例"
onclick="Button1_Click" />
</div>
</div>
</form>
</body>
</html>
.aspx.cs代码例如以下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls; public partial class Sample_3_6 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{ }
protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
//C#中的3元运算符 ：？的使用方法
txt_1.Text = (CheckBox1.Checked) ? "选中状态" : "非选中状态"; }
protected void btn_submit_Click(object sender, EventArgs e)
{ //首先要清空TEXTBOX的内容；以免受上一次操作的影响
TextBox1.Text = "";
CheckBox chk; //foreach语句 ctl是循环的自变量不可被更改；所以要引入还有一个变量chk（控件类型）
foreach (Control ctl in div_chklist.Controls)
{ if (ctl is CheckBox) {
chk = (CheckBox)ctl;
if (chk.Checked) { TextBox1.Text += chk.Text + ","; }
} }
} protected void Button1_Click(object sender, EventArgs e)
{
TextBox1.Text = "";
char[] cA = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray(); foreach (char _ca in cA) {
TextBox1.Text += _ca.ToString() + Convert.ToChar(13); } }
}