下面是用来测试验证码的前台显示代码：其中脚本函数change的作用是实现“看不清楚，换一张的效果”
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="CheckTest.aspx.cs" Inherits="SecurityCodeTest.CheckTest" %>
<!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>
<mce:script type="text/javascript" ><!--
function Change() {
var d = document.getElementById("image1");
d.src = d.src + '?';
}
// --></mce:script>
</head>
<body>
<form id="form1" runat="server">
<img src="MyCode.aspx" mce_src="MyCode.aspx" id="image1" /><asp:LinkButton ID="link1" runat="server" Text="看不清，换一张" OnClientClick="Change()"></asp:LinkButton>
<div><br />
<asp:TextBox ID="input1" runat="server"></asp:TextBox>
<asp:Button ID="button1" runat="server" Text="submit" onclick="button1_Click" />
</div>
</form>
</body>
</html>
下面是用来生成验证码图片的aspx文件代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Drawing;
using System.Drawing.Imaging;
namespace SecurityCodeTest
{
public partial class MyCode1 : System.Web.UI.Page
{
private int _imageWidth = 88;//位图宽度
private int _imageHeight = 25;//位图高度
private Bitmap _bitmap = null;//位图对象
private List<Brush> _colorList = null;//颜色的一个列表
private char[] _charGroup = null;//字符数组
private string fontFamily = "Times New Roman";
/// <summary>
/// 随机获取字体大小
/// </summary>
/// <returns></
