ActiveRecord Enabling lazy load 方案

lazy load AR 官的方案是

            BeginRequest += new EventHandler(OnBeginRequest);
            EndRequest += new EventHandler(OnEndRequest);

            // Initialization code omitted

        }

        protected void Application_End(object sender, EventArgs e)
        {

        }

        public void OnBeginRequest(object sender, EventArgs e)
        {
    //        HttpContext.Current.Items.Add("nh.sessionscope", new SessionScope());
        }

        public void OnEndRequest(object sender, EventArgs e)
        {
            //try
            //{
            //    SessionScope scope = HttpContext.Current.Items["nh.sessionscope"] as SessionScope;
            //    if (scope != null)
            //    {
            //        scope.Dispose();
            //    }
            //}
            //catch (Exception ex)
            //{
            //    HttpContext.Current.Trace.Warn("Error", "EndRequest: " + ex.Message, ex);
            //}
        }

但我用这个办法，后来建了个PageBase.cs

using System;
using System.Data;
using System.Configuration;
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 Castle.ActiveRecord;

namespace Wz16.WebApp
{
    public class PageBase : System.Web.UI.Page
    {
        protected SessionScope CurSessionScope ;
        protected override void OnInit(EventArgs e)
        {
            CurSessionScope = new SessionScope();
            base.OnInit(e);
        }

        public override void Dispose()
        {
            try
            {
                if (CurSessionScope != null)
                {
                    CurSessionScope.Dispose();
                }
            }
            catch (Exception ex)
            {
                HttpContext.Current.Trace.Warn("Error", "EndRequest: " + ex.Message, ex);
            }
            
            base.Dispose();
        }
    }
}

继承自PageBase.cs的页面就都支持 AR 的 Lazy Load

我用的 asp.net2.0 为什么官方的方案会不行，有知道的人请赐教。