using System;

using System.Drawing;
using CB.Common;

namespace CB.Admin
{
    public partial class verifyimage : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string code = Utils.GetRandomInt();
            Utils.WriteCookie("ducenter-code", XXTEA.Encode(code), 5);
            CreateImage(code);
        }

        #region 生成图片验证码
        private void CreateImage(string code)
        {
            if (string.IsNullOrEmpty(code))
                code = "鬼子";

            int randAngle = 45; //随机转动角度
            int mapwidth = (int)(code.Length * 16);
            Bitmap map = new Bitmap(mapwidth, 26);//创建图片背景
            Graphics graph = Graphics.FromImage(map);
            graph.Clear(Color.AliceBlue);//清除画面，填充背景
            graph.DrawRectangle(new Pen(Color.Black, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框
            //graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式
            Random rand = new Random();
            //背景噪点生成
            Pen blackPen = new Pen(Color.LightGray, 0);
            for (int i = 0; i < 50; i++)
            {
                int x = rand.Next(0, map.Width);
                int y = rand.Next(0, map.Height);
                graph.DrawRectangle(blackPen, x, y, 1, 1);
            }
            //验证码旋转，防止机器识别
            char[] chars = code.ToCharArray();//拆散字符串成单字符数组

            //文字距中
            StringFormat format = new StringFormat(StringFormatFlags.NoClip);
            format.Alignment = StringAlignment.Center;
            format.LineAlignment = StringAlignment.Center;
            //定义颜色

            Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };

            //定义字体
            string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
            for (int i = 0; i < chars.Length; i++)
            {
                int cindex = rand.Next(7);
                int findex = rand.Next(5);
                Font f = new System.Drawing.Font(font[findex], 12, System.Drawing.FontStyle.Bold);//字体样式(参数2为字体大小)
                Brush b = new System.Drawing.SolidBrush(c[cindex]);
                Point dot = new Point(13, 13);
                //graph.DrawString(dot.X.ToString(),fontstyle,new SolidBrush(Color.Black),10,150);//测试X坐标显示间距的
                float angle = rand.Next(-randAngle, randAngle);//转动的度数
                graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置
                graph.RotateTransform(angle);
                graph.DrawString(chars[i].ToString(), f, b, 0, 0, format);
                //graph.DrawString(chars[i].ToString(),fontstyle,new SolidBrush(Color.Blue),1,1,format);
                graph.RotateTransform(-angle);//转回去
                graph.TranslateTransform(1, -dot.Y);//移动光标到指定位置
            }
            //graph.DrawString(randomcode,fontstyle,new SolidBrush(Color.Blue),2,2); //标准随机码

            //生成图片
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            map.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
            Response.ClearContent();
            Response.ContentType = "image/gif";
            Response.BinaryWrite(ms.ToArray());
            graph.Dispose();
            map.Dispose();
        }
        #endregion
    }
}