/// <summary>

         /// 生成随机数字

         /// </summary>

         /// <returns>随机数字</returns>

         public string GetCode(int len = )

         {

             string strCode = string.Empty;

             char code;

             int num;

             Random rnd = new Random();

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

             {

                 num = rnd.Next();

                 if (num %  == )

                 {

                     code = (char)('' + (char)(num % ));

                 }

                 else

                 {

                     //code = (char)('0' + (char)(num % 10));

                    code = (char)('A' + (char)(num % ));

                 }

                 strCode += code.ToString();

             }

             return strCode;

         }

         /// <summary>

         /// 生成验证码（保存验证码到图片）

         /// </summary>

         /// <returns>二进制</returns>

         public byte[] ProcessRequestImage(string validateCode)

         {

             HttpContext context = HttpContext.Current;

             using (Bitmap bmp = new Bitmap(validateCode.Length *  + , ))

             {

                 Graphics g = Graphics.FromImage(bmp);

                 g.Clear(Color.White);

                 Random rnd = new Random();

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

                 {

                     int x1 = rnd.Next(bmp.Width);

                     int y1 = rnd.Next(bmp.Height);

                     int x2 = rnd.Next(bmp.Width);

                     int y2 = rnd.Next(bmp.Height);

                     g.DrawLine(new Pen(Color.FromArgb(rnd.Next(), rnd.Next(), rnd.Next())), x1, y1, x2, y2);

                 }

                 g.DrawRectangle(new Pen(Color.FromArgb(rnd.Next(), rnd.Next(), rnd.Next())), new Rectangle(, , bmp.Width - , bmp.Height - ));

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

                 {

                     bmp.SetPixel(rnd.Next(bmp.Width), rnd.Next(bmp.Height), Color.FromArgb(rnd.Next(), rnd.Next(), rnd.Next()));

                 }

                 for (int i = ; i < validateCode.Length; i++)

                 {

                     FontFamily[] familys = FontFamily.Families;

                     FontFamily family = familys[rnd.Next(familys.Length)];

                     g.DrawString(validateCode[i].ToString(), new Font(family, , FontStyle.Bold), new SolidBrush(Color.FromArgb(rnd.Next(), rnd.Next(), rnd.Next())), new PointF( + i * , ));

                 }

                 //保存图片数据

                 MemoryStream stream = new MemoryStream();

                 bmp.Save(stream, ImageFormat.Jpeg);

                 //  输出图片流

                 return stream.ToArray();

             }

         }

      /// <summary>

         /// 验证码

         /// </summary>

         /// <returns></returns>

         public ActionResult VerifyCode()

         {

             h.Base.Public.SecurityCode seCode = new h.Base.Public.SecurityCode();

             var code = seCode.GetCode();

             Session["code"] = code;

             var bytes = seCode.ProcessRequestImage(code);

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

         }

   <div class="pdiv">

                 <input type="image" id="valiCode"     src="/Based/VerifyCode" />

 </div>

 <script>

     (function () {

   //刷新验证码

         var codeUrl = "/Based/VerifyCode";

         $(valiCode).on("click", function () {

             this.src = codeUrl + "?time=" + (new Date()).getTime();

         });

     })(jQuery)

 </script>