Ejemplo n.º 1
0
        public byte[] GetVerifyCode()
        {
            int    codeW    = 80;
            int    codeH    = 30;
            int    fontSize = 16;
            string chkCode  = string.Empty;

            //颜色列表,用于验证码、噪线、噪点
            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            //字体列表,用于验证码
            string[] font = { "Times New Roman" };
            //验证码的字符集,去掉了一些容易混淆的字符
            char[] character = { '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
            Random rnd       = new Random();

            //生成验证码字符串
            for (int i = 0; i < 4; i++)
            {
                chkCode += character[rnd.Next(character.Length)];
            }
            //写入Session、验证码加密
            WebHelper.WriteSession("session_verifycode", Md5.md5(chkCode.ToLower(), 16));
            //创建画布
            Bitmap   bmp = new Bitmap(codeW, codeH);
            Graphics g   = Graphics.FromImage(bmp);

            g.Clear(Color.White);
            //画噪线
            for (int i = 0; i < 3; i++)
            {
                int   x1  = rnd.Next(codeW);
                int   y1  = rnd.Next(codeH);
                int   x2  = rnd.Next(codeW);
                int   y2  = rnd.Next(codeH);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            }
            //画验证码字符串
            for (int i = 0; i < chkCode.Length; i++)
            {
                string fnt = font[rnd.Next(font.Length)];
                Font   ft  = new Font(fnt, fontSize);
                Color  clr = color[rnd.Next(color.Length)];
                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 18, (float)0);
            }
            //将验证码图片写入内存流,并将其以 "image/Png" 格式输出
            MemoryStream ms = new MemoryStream();

            try
            {
                bmp.Save(ms, ImageFormat.Png);
                return(ms.ToArray());
            }
            catch (Exception)
            {
                return(null);
            }
            finally
            {
                g.Dispose();
                bmp.Dispose();
            }
        }