怎么遍历PlaceHolder中动态添加的同一属性控件

using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;

namespace SantGo.Bunli.Web
{

public partial class Site1 : System.Web.UI.MasterPage
{
protected void Page_Load( object sender, EventArgs e )
{
if( !IsPostBack )
{
List<Control> checkBoxList = new List<Control>();

FindSubControls( ContentPlaceHolder1, checkBoxList, new ControlMatchHander( CheckBoxMatchFunc ) );

foreach ( CheckBox checkBox in checkBoxList )
{
divDebug.InnerHtml += string.Format( "{0}, {1}<br /