各类验证码收集 整理笔记

样式一：

protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { this.GenImg(this.GenCode(4)); } } private string GenCode(int num) { string[] source ={"1","2","3","4","5","6","7","8","9", "A","B","C","D","E","F","G","H","I","J","K","L","M","N", "P","Q","R","S","T","U","V","W","X","Y","Z"}; string code = ""; Random rd = new Random(); for (int i = 0; i < num; i++) { code += source[rd.Next(0, source.Length)]; } return code; } //生成图片 private void GenImg(string code) { Bitmap myPalette = new Bitmap(40, 18);

样式二：

protected void Page_Load(object sender, EventArgs e) { CreateCheckCodeImage(GenerateCheckCode()); } //随机生成验证码 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; } //生成验证码图片 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 { Random random = new Random(); g.Clear(Color.White); 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); 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())); } 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(); } }

样式三：

private static Random rnd = new Random(); protected void Page_Load(object sender, EventArgs e) { int width = 60; int height = 20; Bitmap img = new Bitmap(width, height); Graphics g = Graphics.FromImage(img); Brush b; b = new SolidBrush(Color.FromArgb(rnd.Next(200, 250), rnd.Next(200, 250), rnd.Next(200, 250))); g.FillRectangle(b, 0, 0, width, height); Pen p = new Pen(Color.FromArgb(rnd.Next(160, 200), rnd.Next(160, 200), rnd.Next(160, 200))); for (int i = 0; i < 100; i++) { int x1 = rnd.Next(width); int y1 = rnd.Next(height); int x2 = x1 + rnd.Next(12); int y2 = y1 + rnd.Next(12); g.DrawLine(p, x1, y1, x2, y2); } Font f = new Font("Courier New", 16, FontStyle.Bold); PointF pf; StringBuilder sb = new StringBuilder(); for (int i = 0; i < 4; i++) { string s = rnd.Next(10).ToString(); sb.Append(s); b = new SolidBrush(Color.FromArgb(rnd.Next(20, 130), rnd.Next(20, 130), rnd.Next(20, 130))); pf = new PointF(13 * i, -1); g.DrawString(s, f, b, pf); } Session["Captcha"] = sb.ToString(); Response.ContentType = "image/pjpeg"; img.Save(Response.OutputStream, ImageFormat.Jpeg); b.Dispose(); g.Dispose(); img.Dispose(); }

样式四：

protected void Page_Load(object sender, EventArgs e) { System.Random rand = new Random(); int len = rand.Next(4, 6); char[] chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray(); System.Text.StringBuilder myStr = new System.Text.StringBuilder(); for (int iCount = 0; iCount < len; iCount++) { myStr.Append(chars[rand.Next(chars.Length)]); } string text = myStr.ToString(); this.Session["checkcode"] = text; Size ImageSize = Size.Empty; Font myFont = new Font("MS Sans Serif", 12); using (Bitmap bmp = new Bitmap(10, 10)) { using (Graphics g = Graphics.FromImage(bmp)) { SizeF size = g.MeasureString(text, myFont, 5000); ImageSize.Width = (int)size.Width + 1; ImageSize.Height = (int)size.Height + 1; } } using (Bitmap bmp = new Bitmap(ImageSize.Width, ImageSize.Height)) { using (Graphics g = Graphics.FromImage(bmp)) { g.Clear(Color.White); using (StringFormat f = new StringFormat()) { f.Alignment = StringAlignment.Near; f.LineAlignment = StringAlignment.Center; f.FormatFlags = StringFormatFlags.NoWrap; g.DrawString( text, myFont, Brushes.Black, new RectangleF( 0, 0, ImageSize.Width, ImageSize.Height), f); } } int num = ImageSize.Width * ImageSize.Height * 30 / 100; for (int iCount = 0; iCount < num; iCount++) { int x = rand.Next(ImageSize.Width); int y = rand.Next(ImageSize.Height); int r = rand.Next(255); int g = rand.Next(255); int b = rand.Next(255); Color c = Color.FromArgb(r, g, b); bmp.SetPixel(x, y, c); } System.IO.MemoryStream ms = new System.IO.MemoryStream(); bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png); this.Response.ContentType = "image/png"; ms.WriteTo(this.Response.OutputStream); ms.Close(); } myFont.Dispose(); }

感谢http://www.cnblogs.com/baiyuntian/archive/2011/11/10/2244334.html