.net驗證碼代碼

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.IO;
namespace zj123.UI.config
{
    public partial class VilidateCode : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string checkCode = CreateCode(5);
            Session["CheckCode"] = checkCode.ToLower();
            CreateImage(checkCode);
        }

        /*產生驗證碼*/
        public string CreateCode(int codeLength)
        {

            //string so = "2,3,4,5,6,7,8,9,0,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";
            string so = "1,2,3,4,5,6,7,8,9,0";
            string[] strArr = so.Split(',');
            string code = "";
            Random rand = new Random();
            for (int i = 0; i < codeLength; i++)
            {
                code += strArr[rand.Next(0, strArr.Length)];
            }
            return code;
        }

        /*產生驗證圖片*/
        public void CreateImage(string code)
        {

            Bitmap image = new Bitmap(80, 20);
            Graphics g = Graphics.FromImage(image);
            WebColorConverter ww = new WebColorConverter();
            g.Clear((Color)ww.ConvertFromString("#FAE264"));

            Random random = new Random();
            //畫圖片的背景噪音線
            for (int i = 0; i < 12; 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.LightGray), x1, y1, x2, y2);
            }
            Font font = new Font("Arial", 15, FontStyle.Bold | FontStyle.Italic);
            System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(
                new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.Gray, 1.2f, true);
            g.DrawString(code, font, brush, 0, 0);

            //畫圖片的前景噪音點
            //for (int i = 0; i < 10; i++)
            //{
            //    int x = random.Next(image.Width);
            //    int y = random.Next(image.Height);
            //    image.SetPixel(x, y, Color.White);
            //}

            //畫圖片的邊框線
            // g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
            Response.ClearContent();
            Response.ContentType = "image/Gif";
            Response.BinaryWrite(ms.ToArray());
            g.Dispose();
            image.Dispose();
        }
    }

}