1 using System; 2 using System.Collections.Generic; 3 using System.Drawing; 4 using System.Drawing.Imaging; 5 using System.IO; 6 using System.Linq; 7 using System.Web; 8  9 namespace CasCall10 {11     public class service_code : System.Web.UI.Page  12     {13         #region14         public string RandCode()15         {16             int CodeCount = 4;//生成4个随机数  17             string randomChar = "2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";18             randomChar = randomChar.Replace(",", "");19             string RandomCode = "";20             System.Threading.Thread.Sleep(3);21             char[] allCharArray = randomChar.ToCharArray();22             int n = allCharArray.Length;23             System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));24             for (int i = 0; i < CodeCount; i++)25             {26                 int rnd = random.Next(0, n);27                 RandomCode += allCharArray[rnd];28             }29             return RandomCode;30         }31         #endregion32         #region 验证码33         ///  <summary>  34         ///  创建验证码图片  35         ///  </summary>  36         ///  <param  name="randomcode">验证码</param>  37         public byte[] CreateImage(string randomcode)38         {39             int randAngle = 40; //随机转动角度  40             int mapwidth = (int)(randomcode.Length * 18);41             Bitmap map = new Bitmap(mapwidth, 24);//创建图片背景  42             Graphics graph = Graphics.FromImage(map);43             graph.Clear(Color.White);//清除画面，填充背景  44             //graph.DrawRectangle(new Pen(Color.Silver, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框  45 46             Random rand = new Random();47 48             //验证码旋转，防止机器识别  49             char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组  50             //文字距中  51             StringFormat format = new StringFormat(StringFormatFlags.NoClip);52             format.Alignment = StringAlignment.Center;53             format.LineAlignment = StringAlignment.Center;54             //定义颜色  55             Color[] c = { Color.Black, Color.Red, Color.Blue, Color.Green,   56                             Color.Orange, Color.Brown, Color.DarkBlue };57 58             //画图片的背景噪音线  59             for (int i = 0; i < 2; i++)60             {61                 int x1 = rand.Next(10);62                 int x2 = rand.Next(map.Width - 10, map.Width);63                 int y1 = rand.Next(map.Height);64                 int y2 = rand.Next(map.Height);65 66                 graph.DrawLine(new Pen(c[rand.Next(7)]), x1, y1, x2, y2);67             }68 69             for (int i = 0; i < chars.Length; i++)70             {71                 int cindex = rand.Next(7);72                 int findex = rand.Next(5);73                 Font f = new System.Drawing.Font("Arial", 18, System.Drawing.FontStyle.Regular);//字体样式(参数2为字体大小)  74                 Brush b = new System.Drawing.SolidBrush(c[cindex]);75                 Point dot = new Point(12, 16);76                 float angle = rand.Next(-randAngle, randAngle);//转动的度数  77                 graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置  78                 graph.RotateTransform(angle);79                 graph.DrawString(chars[i].ToString(), f, b, 1, 1, format);80                 graph.RotateTransform(-angle);//转回去  81                 graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置  82             }83             //生成图片  84             System.IO.MemoryStream ms = new System.IO.MemoryStream();85             MemoryStream stream = new MemoryStream();86             map.Save(stream, ImageFormat.Jpeg);87             graph.Dispose();88             map.Dispose();89             return stream.ToArray();90 91 92         }93         #endregion  94     }95 }

1  <label class="panel-body">验证码：</label>2  <input type="text" id="yzm" name="yzm" class="form-control" />&nbsp;&nbsp;</td>3  <img id="ValidCode" style="cursor: pointer;" src="/SignIn/YanZhengMa" alt="验证码"  onclick="this.src=http://www.mamicode.com/‘/SignIn/YanZhengMa?time=‘ + new Date().getTime();" />4  <a href="#" id="Changes" data-toggle="modal" data-target="#mymodel">看不清,换一张</a>

$("#Changes").click(function () {        document.getElementById("ValidCode").src = http://www.mamicode.com/‘/SignIn/YanZhengMa?time=‘ + new Date().getTime();>

 1  /// <summary>   2         /// 生成验证码   3         /// </summary>   4         /// <returns></returns>   5         public ActionResult YanZhengMa() 6         { 7             service_code sc = new service_code(); 8             string vVerificationCode = sc.RandCode(); 9             Session["vcode"] = vVerificationCode.ToLower();10            // Safe.SessionAdd("vcode", vVerificationCode.ToLower(), 2);   //Session中保存验证码  11             sc.CreateImage(vVerificationCode);12             return File(sc.CreateImage(vVerificationCode), @"image/jpeg");13         }