验证码帮助类
2013-05-07 16:55 Carl Xing 阅读(195) 评论(0) 编辑 收藏 举报using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Web; using System.Drawing; using System.IO; /// <summary> /// 登陆验证码帮助类 /// </summary> public class LogonValidateCode { /// <summary> /// 比较验证码 /// </summary> /// <param name="inputText">输入的验证码</param> /// <returns>是否验证成功</returns> public static bool CompareCode(string inputText) { bool isMatch = false; if (HttpContext.Current.Request.Cookies["CheckCode"] == null) { HttpContext.Current.Response.Write("<script type='text/javascript'>alert('您的浏览器设置已被禁用 Cookies,您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。')</script>"); return isMatch; } if (String.Compare(HttpContext.Current.Request.Cookies["CheckCode"].Value, inputText, true) != 0) { return isMatch; } isMatch = true; return isMatch; } /// <summary> /// 生成验证码 /// </summary> /// <returns></returns> public static 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(); } //生成的COOKIE HttpContext.Current.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode)); return checkCode; } /// <summary> /// 生产验证码的图片 /// </summary> /// <param name="checkCode">验证码</param> public static 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); DrawCheckCodeImage(image, g, checkCode); System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); //System.Drawing.Bitmap bitImg = new System.Drawing.Bitmap(ms); //bitImg.Save(HttpContext.Current.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); HttpContext.Current.Response.ClearContent(); HttpContext.Current.Response.ContentType = "image/Gif"; HttpContext.Current.Response.BinaryWrite(ms.ToArray()); g.Dispose(); image.Dispose(); } /// <summary> /// 绘制验证码图片 /// </summary> /// <param name="image">Bitmap对象实例</param> /// <param name="g">Graphics对象实例</param> /// <param name="checkCode">验证码</param> private static void DrawCheckCodeImage(Bitmap image, Graphics g, string checkCode) { //清空图片背景色 g.Clear(Color.White); //生成随机生成器 Random random = new Random(); //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.GreenYellow), x1, y1, x2, y2); } //画图片的验证码 Font font = new System.Drawing.Font("Verdana", 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 < 80; 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.Red), 0, 0, image.Width - 1, image.Height - 1); } }