实现一个通用的验证码功能

最新推荐文章于 2024-08-25 09:40:01 发布

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这个功能是网站必备的，自己在网上找了一下，用了些别人的代码，自己再拿到自己的项目中来。做成一个通用的功能模块。

如果需要这个功能的，直接把下面的code copy一下就可以用了。

前台UI

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ValidateCode.aspx.cs" Inherits="UI_ValidateCode" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>实现验证码功能-by wangtao</title>

</head>

<body>

//点击图片改变验证码

$(function(){

$("#validateCode").click(function(){

var src=$(this).attr("src");

src+="?"+Math.random();

$(this).attr("src",src);

})

</script>

<div>

</div>

</form>

</body>

</html>

后台代码：

<%@ WebHandler Language="C#" Class="GetValidateCode" %>

using System;

using System.Web;

using System.Drawing;

public class GetValidateCode : IHttpHandler {

public void ProcessRequest (HttpContext context) {

// context.Response.AddHeader = "";

context.Response.Cache.SetCacheability(HttpCacheability.NoCache);

context.Response.ClearContent();

context.Response.ContentType = "image/gif";

//context.Response.ContentType = "image/Gif";

this.CreateCheckCodeImage(GenerateCheckCode(context), context);

}

public bool IsReusable {

get {

return false;

}

private string GenerateCheckCode(HttpContext context)

{

int number;

char code;

string checkCode = String.Empty;

System.Random random = new Random();

for (int i = 0; i < 4; i++)

{

number = random.Next();

if (number % 2 == 0)

code = (char)('0' + (char)(number % 10));

else if (number % 3 == 0)

code = (char)('A' + (char)(number % 26));

else

code = (char)('a' + (char)(number % 26));

checkCode += code.ToString();

}

context.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));//也可以存到cookie里．

// context.Session["CheckCode"] = checkCode;

// context.Session

return checkCode;

}

private void CreateCheckCodeImage(string checkCode, HttpContext context)

{

if (checkCode == null || checkCode.Trim() == String.Empty)

return;

System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);

Graphics g = Graphics.FromImage(image);

try

{

//生成随机生成器

Random random = new Random();

//清空图片背景色

g.Clear(Color.White);

//画图片的背景噪音线

for (int i = 0; i < 25; i++)

{

int x1 = random.Next(image.Width);

int x2 = random.Next(image.Width);

int y1 = random.Next(image.Height);

int y2 = random.Next(image.Height);

g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);

}

Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));

System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);

g.DrawString(checkCode, font, brush, 2, 2);

//画图片的前景噪音点

for (int i = 0; i < 100; i++)

{

int x = random.Next(image.Width);

int y = random.Next(image.Height);

image.SetPixel(x, y, Color.FromArgb(random.Next()));

}

//画图片的边框线

g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

System.IO.MemoryStream ms = new System.IO.MemoryStream();

image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);

//context.Response.ClearContent();

//context.Response.ContentType = "image/Gif";

context.Response.BinaryWrite(ms.ToArray());

}

finally

{

g.Dispose();

image.Dispose();

}