using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

using System.Web.SessionState;
using System.Drawing;
using System.Drawing.Imaging;
 

namespace FyCms.Web
{
    public partial class ImgCode : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            DrawCode();
        }
        public void DrawCode()
        {
            int width = 65;
            int height = 25;
            //定义一个随机变量
            Random rand = new Random();

            //创建图象
            Bitmap img = new Bitmap(width, height);

            //从图象上获取一个绘画图
            Graphics g = Graphics.FromImage(img);

            try
            {
                //定义字体
                Font font = new Font("Comic sans ms", 11, FontStyle.Bold);



                Font font = new Font(FontItems[fontIndex], 11, return FontStyle.Regular | FontStyle.Bold;);


                //定义黑色画笔
                SolidBrush brush = new SolidBrush(Color.Black);


                //定义钢笔,绘制干扰线
                Pen pen1 = new Pen(Color.Gray);
                Pen pen2 = new Pen(Color.Gray);


                //清除整个绘画图面并以指定颜色填充
                g.Clear(ColorTranslator.FromHtml("#FFFFFF"));

                //定义文字的绘制矩形区域
                Rectangle rect = new Rectangle(2, 2, width, height);

                //定义一个随机数用于绘制干扰线


                //生成两条横向干扰线
                for (int i = 0; i < 2; i++)
                {
                    //Define Point1
                    Point p1 = new Point(0, rand.Next(height));
                    //Define Point2
                    Point p2 = new Point(width, rand.Next(height));

                    g.DrawLine(pen1, p1, p2);
                }

                //生成四条纵向干扰线
                for (int i = 0; i < 4; i++)
                {
                    //Define Point1
                    Point p1 = new Point(rand.Next(width), 0);
                    //Define Point2
                    Point p2 = new Point(rand.Next(width), height);

                    //DrawLine
                    g.DrawLine(pen2, p1, p2);
                }
                string strsj = strRand();
                g.DrawString(strsj, font, brush, rect);

                //输出图象            
                img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
                Session["ImgCode"] = strsj.ToLower();
                //return strRand().ToLower();
            }
            catch (Exception error)
            {
                throw new Exception(error.Message);
            }
            finally
            {
                g.Dispose();
                img.Dispose();
            }
        }

        //产生随机数
        public string strRand()
        {   //验证码范围
            char[] strCode = { 
                               '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 strRandomCode = "";

            Random random = new Random();
            if (Session["ImgCode"] == null)
            {
                for (int i = 0; i < 4; i++)
                {
                    strRandomCode += strCode[random.Next(strCode.Length)];
                   
                }
                
            }
            else
            {

                strRandomCode += S