验证码代码

验证码代码 using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Drawing; //Ìí?ÓÒýÓà public partial class yzm : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { CreateCheckCodeImage(GenerateCheckCode()); } private string GenerateCheckCode() { int number; char code; string checkCode = String.Empty; Random random = new Random(); for (int i = 0; i < 4; i++) { number = random.Next(); code = (char)('0' + (char)(number % 10)); 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 { //Éú?ÉËæ?úÉú?ÉÆ? Random random = new Random(); //Çå?ÕÍ?Æ?????É? g.Clear(Color.White); //?,Í?Æ?µÄ????ÔëÒôÏß for (int i = 0; i < 2; 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.Black), x1, y1, x2, y2); } Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold)); 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); //?,Í?Æ?µÄÇ???ÔëÒôµã 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())); } //?,Í?Æ?µÄ?ß?òÏß 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.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } }