using System;

using System.Collections.Generic;

using System.Drawing;

using System.Drawing.Imaging;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace 落地页测试代码

{

    public class VerifyCode

    {

        public byte[] GetVerifyCode()

        {

            int codeW = ;

            int codeH = ;

            int fontSize = ;

            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 = { '', '', '', '', '', '', '', '', '', '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 = ; i < ; i++)

            {

                chkCode += character[rnd.Next(character.Length)];

            }

            //写入Session、验证码MD5加密

            WebHelper.WriteSession("nfine_session_verifycode", Md5.md5(chkCode.ToLower(), ));

            //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 = ; i < ; 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 = ; 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 * , (float));

            }

            //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();

            }

        }

    }

}