ASP.net下DataGrid的单项选择控件

#region 声明
//----------------------------------------------------------------------
//
// 作者: 李淼（Nick.Lee）
//
// ASP.net下DataGrid的单项选择控件

// 时间:2005-3-15

// boyorgril@msn.com
// QQ:16503096
//注意：引用请标明出处,谢谢
//----------------------------------------------------------------------
#endregion

javascript:window.open(this.src);" style="cursor:pointer;"/>

前台：

<%@ Control Language="c#" AutoEventWireup="false" Codebehind="WebUserControl1.ascx.cs" Inherits="message1.WebUserControl1" TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
<LINK href="xpTable.css" type="text/css" rel="stylesheet">
<asp:DataGrid id="DataGrid1" runat="server" BorderStyle="None" BorderWidth="1px" CellPadding="4"
 Font-Size="9pt" Width="70%" BorderColor="#3366CC">
 <SelectedItemStyle Font-Bold="True" ForeColor="#CCFF99" BackColor="#009999"></SelectedItemStyle>
 <ItemStyle ForeColor="#003399" BackColor="White"></ItemStyle>
 <HeaderStyle Font-Bold="True" ForeColor="#CCCCFF" BackColor="#003399"></HeaderStyle>
 <FooterStyle ForeColor="#003399" BackColor="#99CCCC"></FooterStyle>
 <Columns>
  <asp:TemplateColumn>
   <ItemTemplate>
     <INPUT type=radio value='<%# DataBinder.Eval(Container.DataItem, "Volume")%>' name=RadioName>
   </ItemTemplate>
  </asp:TemplateColumn>
 </Columns>
 <PagerStyle HorizontalAlign="Left" ForeColor="#003399" BackColor="#99CCCC" Mode="NumericPages"></PagerStyle>
</asp:DataGrid>
<asp:Button id="Button1" runat="server" Text="Button"></asp:Button><INPUT id="rd" type="hidden" name="rd" runat="server">
<asp:Label id="Label1" runat="server">Label</asp:Label>

后台：

namespace message1
{
 using System;
 using System.Data;
 using System.Drawing;
 using System.Web;
 using System.Web.UI.WebControls;
 using System.Web.UI.HtmlControls;
 using System.Data.OleDb;
 using System.ComponentModel;

 using NickLee.Web.UI;

 /// <summary>
 ///  WebUserControl1 的摘要说明。
 /// </summary>
 public class WebUserControl1 : System.Web.UI.UserControl
 {
  protected System.Web.UI.WebControls.DataGrid DataGrid1;
  protected System.Web.UI.HtmlControls.HtmlInputHidden rd;
  protected System.Web.UI.WebControls.Label Label1;
  public DataSet custDS = new DataSet();
  protected System.Web.UI.WebControls.Button Button1;

  private string sql;
  public string Sql
  {
   get{return sql;}
   set{sql=value;}
  }

  //------------------------------------------------------------------------------------
  /// <summary>
  /// 窗体名
  /// </summary>
  System.Web.UI.Page _page;
  [BrowsableAttribute(true),CategoryAttribute("Appearance"),BindableAttribute(true)]