复选框列表在更新面板中不起作用

Question

我已在网页的更新面板中创建了复选框列表，如下所示

在aspx文件中

              <asp:UpdatePanel ID="pnlUpdateAgency" runat="server">
              ...
               <asp:CheckBoxList ID="chklLineOfAuthority"   RepeatColumns="3" RepeatLayout="Table"
               RepeatDirection="Horizontal" AutoPostBack="false" CausesValidation="false" runat="server">
              </asp:CheckBoxList>             
              ...
              </asp:UpdatePanel>

在aspx.cs文件中

              Page_Load(...)
              {
               ...
               ...
                int pid = 2045;
               FillLineOfAuthorityForProduct(pid);
              }
               public void FillLineOfAuthorityForProduct(int productid)
               {
               DataSet ds = new DataSet();
               LineOfAuthorityBL bl = new LineOfAuthorityBL(SessionContext.SystemUser);
               bl.FetchAll(ds);
               chklLineOfAuthority.DataSource = ds.Tables[bl.SqlEntityX];
               chklLineOfAuthority.DataTextField = "LineOfAuthorityX";
               chklLineOfAuthority.DataBind();
               ds = null;

              DataSet dss = new DataSet();
              bl.FetchForProductId(dss, productid);
             if (dss.Tables[0].Rows.Count > 0)
             {
            string[] arrGroup = dss.Tables[0].Rows[0]["LineOfAuthorityX"].ToString().Split(',');

            foreach (object obj in arrGroup)
            {

                for (int i = 0; i < chklLineOfAuthority.Items.Count; i++)
                {
                    if (chklLineOfAuthority.Items[i].Value == obj.ToString())
                    {
                        chklLineOfAuthority.Items[i].Selected = true;
                    }
                }
            }
        }

    }                 

现在问题是没有在网页中检查复选框... 请帮帮我!!!