ASP.NET MVC 模块与组件（二）——定制图片验证码

　　本着简洁直接，我们就直奔主题吧！

　　下面是一个生成数字和字母随机组合的验证码类源代码：

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Web.UI;

using System.Drawing.Drawing2D;

using System.IO;

namespace Forcheng.Code

{

    /// <summary>

    /// 生成验证码的类

    /// </summary>

    public class ValidateCode

    {

        /// <summary>

        /// 生成验证码

        /// </summary>

        /// <param name="length">指定验证码的长度</param>

        /// <returns></returns>

        public string CreateValidateCode(int length)

        {

            const string validateTemplate = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ";

            string validateStr = "";

            int n = validateTemplate.Length - ;

            //设置随机值生成器

            int seekSeek = unchecked((int)DateTime.Now.Ticks);

            Random seekRand = new Random(seekSeek);

            int beginSeek = ;

            //生成随机验证码

            for (int i = ; i < length; i++)

            {

                beginSeek = seekRand.Next(, n);

                validateStr += validateTemplate.Substring(beginSeek, );

            }

            return validateStr;

        }

        /// <summary>

        /// 创建验证码的图片

        /// </summary>

        /// <param name="containsPage">要输出到的page对象</param>

        /// <param name="validateNum">验证码</param>

        public byte[] CreateValidateGraphic(string validateCode)

        {

            Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 13.0), );

            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);

                //画图片的干扰线

                for (int i = ; i < ; 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 Font("Arial", , (FontStyle.Bold | FontStyle.Italic));

                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(, , image.Width, image.Height),

                 Color.Blue, Color.DarkRed, 1.2f, true);

                g.DrawString(validateCode, font, brush, , );

                //画图片的前景干扰点

                for (int i = ; i < ; 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), , , image.Width - , image.Height - );

                //保存图片数据

                MemoryStream stream = new MemoryStream();

                image.Save(stream, ImageFormat.Jpeg);

                //输出图片流

                return stream.ToArray();

            }

            finally

            {

                g.Dispose();

                image.Dispose();

            }

        }

    }

}

　　下面是使用验证码类的后台实例代码（生成一个5位的图片验证码）：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

using System.Web.Security;

using Forcheng.Code;

namespace Test.Controllers

{

    public class HomeController : Controller

    {

       /// <summary>

        /// 获取图片验证码

        /// </summary>

        /// <returns></returns>

        public ActionResult GetValidateCode(string codeClass)

        {

            ValidateCode vCode = new ValidateCode();

            string code = vCode.CreateValidateCode();

            byte[] bytes = vCode.CreateValidateGraphic(code);

            return File(bytes, @"image/jpeg");

        }

    }

}

　　下面是前台页面使用的实例代码：

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

    <head>

        <title>图片验证码</title>

    </head>

    <body>

        <img id="valiCode" class="validcode" src="/Home/GetValidateCode" alt="验证码" title="点击刷新" />

        <script type="text/javascript">

        $(document).ready(function () {

            $("#valiCode").bind("click", function () {

            this.src = "/Home/GetValidateCode?&time=" + (new Date()).getTime();

        });

        });

        </script>

    </body>

</html>

　　效果截图（做的另一个找回密码页面，不是上面的前台代码效果）：

　　 ASP.NET MVC 模块与组件（二）——定制图片验证码

　　　这次的分享就到这吧，我们下次继续。

　　<我的博客主页>:http://www.cnblogs.com/forcheng/