public void CreateValidateCode() { ValidateCoder vc = new ValidateCoder(); string code = vc.CreateValidateCode(4); Session["ValidateCode"] = code; byte[] bytes = vc.CreateValidateGraphic(code); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(bytes); Response.Flush(); Response.End(); }
/// <summary> /// 创建验证码的图片 /// </summary> /// <param name="validateCode">验证码</param> /// <param name="hasBorder">是否需要画边框</param> public byte[] CreateValidateGraphic(string validateCode, bool hasBorder = false) { Bitmap image = new Bitmap(ValidateCoder.GetImageWidth(validateCode.Length), ValidateCoder.GetImageHeight()); 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); //画图片的干扰线 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 Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic)); LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true); g.DrawString(validateCode, font, brush, 3, 2); //画图片的前景干扰点 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 if (hasBorder) { g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); } //保存图片数据 MemoryStream stream = new MemoryStream(); image.Save(stream, ImageFormat.Jpeg); //输出图片流 return(stream.ToArray()); } finally { g.Dispose(); image.Dispose(); } }