MVC3 验证码

生成验证码：

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Web;  
using System.Drawing;  
using System.Drawing.Drawing2D;  
using System.IO;  
using System.Drawing.Imaging;  
  
namespace TestMVC3.Helpers  
{ 
    /// <summary>   
    /// 生成验证码的类   
    /// </summary>   
    public class ValidateCode  
    {  
        public ValidateCode()  
        {  
        }  
        /// <summary>   
        /// 验证码的最大长度   
        /// </summary>   
        public int MaxLength  
        {  
            get { return 10; }  
        }  
        /// <summary>   
        /// 验证码的最小长度   
        /// </summary>   
        public int MinLength  
        {  
            get { return 1; }  
        }  
        /// <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)  
        {  
            int[] randMembers = new int[length];  
            int[] validateNums = new int[length];  
            string validateNumberStr = "";  
            //生成起始序列值   
            int seekSeek = unchecked((int)DateTime.Now.Ticks);  
            Random seekRand = new Random(seekSeek);  
            int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);  
            int[] seeks = new int[length];  
            for (int i = 0; i < length; i++)  
            {  
                beginSeek += 10000;  
                seeks[i] = beginSeek;  
            }  
            //生成随机数字   
            for (int i = 0; i < length; i++)  
            {  
                Random rand = new Random(seeks[i]);  
                int pownum = 1 * (int)Math.Pow(10, length);  
                randMembers[i] = rand.Next(pownum, Int32.MaxValue);  
            }  
            //抽取随机数字   
            for (int i = 0; i < length; i++)  
            {  
                string numStr = randMembers[i].ToString();  
                int numLength = numStr.Length;  
                Random rand = new Random();  
                int numPosition = rand.Next(0, numLength - 1);  
                validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));  
            }  
            //生成验证码   
            for (int i = 0; i < length; i++)  
            {  
                validateNumberStr += validateNums[i].ToString();  
            }  
            return validateNumberStr;  
        }  
        /// <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 * 12.0), 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);  
                //画图片的干扰线   
                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 Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));  
                LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),  
                 Color.Blue, Color.DarkRed, 1.2f, true);  
                g.DrawString(validateCode, font, brush, 3, 2);  
                //画图片的前景干扰点   
                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);  
                //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();  
            }  
        }  
  
        /// <summary>   
        /// 得到验证码图片的长度   
        /// </summary>   
        /// <param name="validateNumLength">验证码的长度</param>   
        /// <returns></returns>   
        public static int GetImageWidth(int validateNumLength)  
        {  
            return (int)(validateNumLength * 12.0);  
        }  
        /// <summary>   
        /// 得到验证码的高度   
        /// </summary>   
        /// <returns></returns>   
        public static double GetImageHeight()  
        {  
            return 22.5;  
        }  
    }  
}  

控制层：

public ActionResult GetValidateCode()  
    {  
        ValidateCode vCode = new ValidateCode();  
        string code = vCode.CreateValidateCode(5);  
        Session["ValidateCode"] = code;  
        byte[] bytes = vCode.CreateValidateGraphic(code);  
        return File(bytes, @"image/jpeg");  
    }

视图层：

<p>
<img id="valiCode" style="cursor: pointer;" src="/Home/GetValidateCode" alt="验证码" />
</p>

<script>
    $(function () {  
        $("#valiCode").bind("click", function () {  
            this.src = "/Home/GetValidateCode?time=" + (new Date()).getTime();  
        });  
    });<script>