using System;  using System.Data;  using System.Configuration;  using System.Web;  using System.Web.Security;  using System.Web.UI;  using System.Web.UI.WebControls;  using System.Web.UI.HtmlControls;  using System.Drawing;    //powered by http://outofmemory.cn/  namespace AppUtility.Tools  {      /// <summary>      /// VerifyCode 的摘要说明。      /// </summary>      public class VerifyCodeImgHelper      {          public VerifyCodeImgHelper()          {              //              // TODO: 在此处添加构造函数逻辑              //          }            #region 验证码长度(默认4个验证码的长度)          int length = 4;          public int Length          {            get { return length; }            set { length = value; }          }          #endregion            #region 验证码字体大小默认11像素          int fontSize = 11;          public int FontSize          {              get { return fontSize; }              set { fontSize = value; }          }          #endregion            #region 边框补          int padding = 1;          public int Padding          {              get { return padding; }              set { padding = value; }          }          #endregion            #region 是否输出燥点(默认不输出)          bool chaos = true;          public bool Chaos          {              get { return chaos; }              set { chaos = value; }          }          #endregion            #region 输出燥点的颜色(默认灰色)          Color chaosColor = Color.LightGray;          public Color ChaosColor          {              get { return chaosColor; }              set { chaosColor = value; }          }          #endregion            #region 自定义背景色(默认白色)          Color backgroundColor = Color.White;          public Color BackgroundColor          {              get { return backgroundColor; }              set { backgroundColor = value; }          }          #endregion            #region 自定义随机颜色数组          Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.DarkMagenta, Color.Brown, Color.DarkCyan, Color.Purple };          public Color[] Colors          {              get { return colors; }              set { colors = value; }          }          #endregion            #region 自定义字体数组          string[] fonts = { "Gautami","Tahoma","宋体" };          public string[] Fonts          {              get { return fonts; }              set { fonts = value; }          }          #endregion            #region 自定义随机码字符串序列(使用逗号分隔)          string codeSerial = "a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,2,3,4,5,s,t,u,v,w,x,y,z,6,7,8,A,B,D,E,F,G,H,K,M,N,Q";//          public string CodeSerial          {              get { return codeSerial; }              set { codeSerial = value; }          }          #endregion            #region 生成校验码图片          public Bitmap CreateImageCode(string code)          {              int fSize = FontSize;              int fWidth = fSize + Padding;              int imageWidth = 60;              int imageHeight = 25;              System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);              Graphics g = Graphics.FromImage(image);              g.Clear(BackgroundColor);              Random rand = new Random();              //给背景添加随机生成的燥点              if (this.Chaos)              {                  Pen pen = new Pen(ChaosColor, 0);                  int c = Length * 10;                  for (int i = 0; i < c; i++)                  {                      int x = rand.Next(image.Width);                      int y = rand.Next(image.Height);                      g.DrawRectangle(pen, x, y, 1, 1);                  }              }              int left = 0, top = 0;                Font f;              Brush b;              int cindex, findex;              //随机字体和颜色的验证码字符              for (int i = 0; i < code.Length; i++)              {                  cindex = rand.Next(Colors.Length - 1);                  findex = rand.Next(Fonts.Length - 1);                    f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);                  b = new System.Drawing.SolidBrush(Colors[cindex]);                  if (i % 2 == 1)                  {                      top = 2;                  }                  else                  {                      top = 1;                  }                    left = i * fWidth;                  g.DrawString(code.Substring(i, 1), f, b, left, top);              }              //画一个边框边框颜色为Color.Gainsboro              g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);              g.Dispose();              return image;          }          #endregion            #region 将创建好的图片输出到页面          public void CreateImageOnPage(string code, HttpContext context)          {              using (System.IO.MemoryStream ms = new System.IO.MemoryStream())              {                  using (Bitmap image = this.CreateImageCode(code))                  {                      image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);                      context.Response.ClearContent();                      context.Response.ContentType = "image/Jpeg";                      context.Response.BinaryWrite(ms.GetBuffer());                      ms.Close();                  }              }          }          #endregion            #region 生成随机字符码          public string CreateVerifyCode(int codeLen)          {              if (codeLen == 0)              {                  codeLen = Length;              }              string[] arr = CodeSerial.Split(',');              string code = "";              int temp = -1;              Random rand = new Random();              for (int i = 0; i < codeLen; i++)              {                  if (temp != -1)                  {                      rand = new Random(temp * i * ((int)DateTime.Now.Ticks));                  }                    int t = rand.Next(arr.Length-1);                    while (temp == t)                  {                      t = rand.Next(arr.Length-1);                  }                    temp = t;                  code += arr[t];              }                return code;          }            #endregion        }  }