子类的Page_Load没有被触发,该如何解决

public partial class BasePage : Page    {        protected override void OnLoad(EventArgs e)        {            // 业务逻辑            base.OnLoad(e);        }        public string BaseUrl { get; set; }    }public partial class Login : BasePage    {        protected override void Page_Load(object sender, EventArgs e)        {            -- 此处程序都没有执行到            if (!IsPostBack) -- 断点在这里            {                string strUserID = string.Empty;                if (Request.Params["userid"] != null)                {                    strUserID = Request.Params["userid"].ToString();                }            }        }    }

public class BasePage:Page    {        public BasePage()         {            this.Load += new EventHandler(CheckSession_Load);            //PublicMethods.ReturnClientPosition(this);        }        //protected override void OnInit(EventArgs e)        //{        //    this.Load += new EventHandler(CheckSession_Load);        //    base.OnInit(e);        //}        //protected override void OnLoad(EventArgs e)        //{        //    //一些要在Page_Load的时候执行的代码        //    base.OnLoad(e);        //}        /// <summary>        /// 用来判断session是否还保持        /// </summary>        protected void CheckSession_Load(object sender, EventArgs e)         {            PublicMethods.IsSessionActive(this);        }           }