ASP.NET（VS）验证码生成

一。
/////////////////////////////////////verifCode.aspx.cs/////////////////////////////////////////////////////////////
using System; 
using System.Collections; 
using System.ComponentModel; 
using System.Data; 
using System.Web; 
using System.Web.SessionState; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.HtmlControls; 
using System.Drawing; 
using System.Drawing.Imaging; 
using System.Drawing.Text;


namespace SaYoyo_Travel2
{
    public partial class verifCode : System.Web.UI.Page
    {


        static string[] FontItems = new string[] { "Arial","Helvetica","Geneva","sans-serif","Verdana"};
        static Brush[] BrushItems = new Brush[] { Brushes.OliveDrab,Brushes.ForestGreen,Brushes.DarkCyan,Brushes.LightSlateGray,Brushes.RoyalBlue,Brushes.SlateBlue,Brushes.DarkViolet,Brushes.MediumVioletRed,Brushes.IndianRed,Brushes.Firebrick,Brushes.Chocolate,Brushes.Peru,Brushes.Goldenrod};
        static string[] BrushName = new string[] { "OliveDrab","ForestGreen","DarkCyan","LightSlateGray","RoyalBlue","SlateBlue","DarkViolet", "MediumVioletRed","IndianRed","Firebrick","Chocolate","Peru","Goldenrod"};
        private static Color BackColor = Color.White;
        private static Pen BorderColor = Pens.DarkGray;
        private static int Width = 52;//画布宽
        private static int Height = 21;//高
        private Random _random;

        private string _code;
        private int _brushNameIndex;        
        /// <summary> 
        /// 
        /// </summary> 
        /// <param name="sender"></param> 
        /// <param name="e"></param> 
        public void Page_Load(object sender, System.EventArgs e)
        {
            if (!IsPostBack)
            {
                this._random = new Random();
                this._code = GetRandomCode();
                // 用Session["code"] 保存验证码 
                Session["code"] = this._code;
                // 输出验证码图片
                this.SetPageNoCache();
                this.OnPaint();
            }
        }

        /// <summary> 
        /// 设置页面不被缓存 
        /// </summary> 
        private void SetPageNoCache()
        {
            Response.Buffer = true;
            Response.ExpiresAbsolute = System.DateTime.Now.AddSeconds(-1);
            Response.Expires = 0;
            Response.CacheControl = "no-cache";