验证码的html怎么写
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<!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>
<title>JS生成验证码</title>
<style type="text/css">
.code {
background-image: url(code.jpg);
font-family: Arial;
font-style: italic;
color: Red;
border: 0;
padding: 2px 3px;
letter-spacing: 3px;
font-weight: bolder;
}
.unchanged {
border: 0;
}
</style>
<script language="javascript" type="text/javascript">
var code; //在全局 定义验证码
function createCode() {
code = "";
var codeLength = 6;//验证码的长度
var checkCode = document.getElementById("checkCode");
var selectChar = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');//所有候选组成验证码的字符，当然也可以用中文的
for (var i = 0; i < codeLength; i++) {
var charIndex = Math.floor(Math.random() * 36);
code += selectChar[charIndex];
}
//alert(code);
if (checkCode) {
checkCode.className = "code";
checkCode.value = code;
}
}
function validate() {
var inputCode = document.getElementById("input1").value;
if (inputCode.length <= 0) {
alert("请输入验证码！");
} else if (inputCode != code) {
alert("验证码输入错误！");
createCode();//刷新验证码
} else {
alert("^-^ OK");
}
}
</script>
</head>
<body onload="createCode()">
<form action="#">
<input type="text" id="input1" /> <input type="text" onclick="createCode()" readonly="readonly" id="checkCode" class="unchanged" style="width: 80px" /><br />
<input id="Button1" onclick="validate();" type="button" value="确定" />
</form>
</body>
</html>
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using System;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class GenerateCheckCode : System.Web.UI.Page
...{
protected void Page_Load(object sender, EventArgs e)
...{
string chkCode = string.Empty;
//颜色列表，用于验证码、噪线、噪点
Color[] color =...{ Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
//字体列表，用于验证码
string[] font =...{ "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" };
//验证码的字符集，去掉了一些容易混淆的字符
char[] character =...{ '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
Random rnd = new Random();
//生成验证码字符串
for (int i = 0; i < 4; i++)
...{
chkCode += character[rnd.Next(character.Length)];
}
Bitmap bmp = new Bitmap(100, 40);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
//画噪线
for (int i = 0; i < 10; i++)
...{
int x1 = rnd.Next(100);
int y1 = rnd.Next(40);
int x2 = rnd.Next(100);
int y2 = rnd.Next(40);
Color clr = color[rnd.Next(color.Length)];
g.DrawLine(new Pen(clr), x1, y1, x2, y2);
}
//画验证码字符串
for (int i = 0; i < chkCode.Length; i++)
...{
string fnt = font[rnd.Next(font.Length)];
Font ft = new Font(fnt, 18);
Color clr = color[rnd.Next(color.Length)];
g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, (float)8);
}
//画噪点
for (int i = 0; i < 100; i++)
...{
int x = rnd.Next(bmp.Width);
int y = rnd.Next(bmp.Height);
Color clr = color[rnd.Next(color.Length)];
bmp.SetPixel(x, y, clr);
}
//清除该页输出缓存，设置该页无缓存
Response.Buffer = true;
Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
Response.Expires = 0;
Response.CacheControl = "no-cache";
Response.AppendHeader("Pragma", "No-Cache");
//将验证码图片写入内存流，并将其以 "image/Png" 格式输出
MemoryStream ms = new MemoryStream();
try
...{
bmp.Save(ms, ImageFormat.Png);
Response.ClearContent();
Response.ContentType = "image/Png";
Response.BinaryWrite(ms.ToArray());
}
finally
...{
//显式释放资源
bmp.Dispose();
g.Dispose();
}
}
}
使用方法如下：
新建名为 GenerateCheckCode.aspx 的文件，将上述代码拷贝到代码文件 GenerateCheckCode.aspx.cs
在需要验证码的地方放置语句 <asp:Image ID="img1" runat="server" ImageUrl="~/GenerateCheckCode.aspx" /> 即可。
