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kuai8 - 2008-10-13 15:45:00
public class ValidateCode : System.Web.UI.Page
  {
  private void Page_Load(object sender, System.EventArgs e)
  {
  this.CreateCheckCodeImage(GenerateCheckCode());
  }
 
  #region web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
  //
  // CODEGEN: 该调用是 asp.NET web 窗体设计器所必需的。
  //
  InitializeComponent();
  base.OnInit(e);
  }
 
  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
  this.Load += new System.EventHandler(this.Page_Load);
  }
  #endregion
 
  private string GenerateCheckCode()
  {
  int number;
  char code;
  string checkCode = String.Empty;
 
  System.Random random = new Random();
 
  for(int i=0; i<5; i++)
  {
  number = random.Next();
 
  if(number % 2 == 0)
  code = (char)('0' + (char)(number % 10));
  else
  code = (char)('A' + (char)(number % 26));
 
  checkCode += code.ToString();
  }
 
  Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
 
  return checkCode;
  }
 
  private void CreateCheckCodeImage(string checkCode)
  {
  if(checkCode == null || checkCode.Trim() == String.Empty)
  return;
 
  System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 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);
 
  //画图片的背景噪音线
  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 System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
  System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
  g.DrawString(checkCode, font, brush, 2, 2);
 
  //画图片的前景噪音点
  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);
 
  System.IO.MemoryStream ms = new System.IO.MemoryStream();
  image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
  Response.ClearContent();
  Response.C;
  Response.BinaryWrite(ms.ToArray());
  }
  finally
  {
  g.Dispose();
  image.Dispose();
  }
  }
  }
cznfh - 2008-10-18 21:29:00
谢谢楼主分享.
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