<img id="vcodeimg" src="/Home/VCode" width="70"
                                    height="25" />
                                 <span
                                    style="cursor: pointer; text-decoration: underline">换一张</span>

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using Utility; using Jellal**; namespace sjlwebsite.Controllers {     public class CommonController : Controller     {         #region 验证码         [OutputCache(Duration = 0)]         public ActionResult VCode()         {             string code = ValidateCode.CreateRandomCode(4);             Session["vcode"] = code;             ValidateCode.CreateImage(code);             return View();         } 。

  。

        public string GetCode()         {             return Session["vcode"].ToStr();         }         #endregion     } } 。

using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; namespace Utility {     ///  <summary>       ///  完美随机验证码  0.10       ///  Verion:0.10       ///  Description:随机生成设定验证码，并随机旋转一定角度，字体颜色不同       ///  </summary>       public class ValidateCode     {         ///  <summary>           ///  生成随机码           ///  </summary>           ///  <param  name="length">随机码个数www.zzvips.com</param>           ///  <returns></returns>           public static string CreateRandomCode(int length)         {             int rand;             char code;             string randomcode = String.Empty;             //生成一定长度的验证码               System.Random random = new Random();             for (int i = 0; i < length; i++)             {                 rand = random.Next();                 if (rand % 3 == 0)                 {                     code = (char)('A' + (char)(rand % 26));                 }                 else                 {                     code = (char)('0' + (char)(rand % 10));                 }                 randomcode += code.ToString();             }             return randomcode;         }         ///  <summary>           ///  创建随机码图片           ///  </summary>           ///  <param  name="randomcode">随机码</param>           public static void CreateImage(string randomcode)         {             int randAngle = 45; //随机转动角度               int mapwidth = (int)(randomcode.Length * 23);             Bitmap map = new Bitmap(mapwidth, 28);//创建图片背景               Graphics graph = Graphics.FromImage(map);             graph.Clear(Color.AliceBlue);//清除画面，填充背景               graph.DrawRectangle(new Pen(Color.Black, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框               //graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式               Random rand = new Random();             //背景噪点生成    www.zzvips.com             Pen blackPen = new Pen(Color.LightGray, 0);             for (int i = 0; i < 50; i++)             {                 int x = rand.Next(0, map.Width);                 int y = rand.Next(0, map.Height);                 graph.DrawRectangle(blackPen, x, y, 1, 1);             }             //验证码旋转，防止机器识别                 char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组               //文字距中               StringFormat format = new StringFormat(StringFormatFlags.NoClip);             format.Alignment = StringAlignment.Center;             format.LineAlignment = StringAlignment.Center;             //定义颜色               Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };             //定义字体               string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };             for (int i = 0; i < chars.Length; i++)             {                 int cindex = rand.Next(7);                 int findex = rand.Next(5);                 Font f = new System.Drawing.Font(font[findex], 13, System.Drawing.FontStyle.Bold);//字体样式(参数2为字体大小)                   Brush b = new System.Drawing.SolidBrush(c[cindex]);                 Point dot = new Point(16, 16);                 //graph.DrawString(dot.X.ToString(),fontstyle,new SolidBrush(Color.Black),10,150);//测试X坐标显示间距的                   float angle = rand.Next(-randAngle, randAngle);//转动的度数                   graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置                   graph.RotateTransform(angle);                 graph.DrawString(chars.ToString(), f, b, 1, 1, format);                 //graph.DrawString(chars.ToString(),fontstyle,new SolidBrush(Color.Blue),1,1,format);                   graph.RotateTransform(-angle);//转回去                   graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置               }             //graph.DrawString(randomcode,fontstyle,new SolidBrush(Color.Blue),2,2); //标准随机码               //生成图片               System.IO.MemoryStream ms = new System.IO.MemoryStream();             map.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);             HttpContext.Current.Response.ClearContent();             HttpContext.Current.Response.ContentType = "image/gif";             HttpContext.Current.Response.BinaryWrite(ms.ToArray());             graph.Dispose();             map.Dispose();         } 。

  。

    } } 。