联动控件问题，老大们进来看看代码？
我想把联动的两个DropDownList放到1个ascx控件中，然后写上属性，方便调用，但是取值和设置值这两个功能都不能实现。大家帮忙看看
这个是Test.ascx文件
<%@ Control Language= "C# " AutoEventWireup= "true " CodeFile= "Test.ascx.cs " Inherits= "Test " %>
<table>
<tr>
<td>
<asp:DropDownList ID= "DropDownList1 " runat= "server " onChange= "redirect(this.options.selectedIndex) ">
</asp:DropDownList>
</td>
<td>
<asp:DropDownList ID= "DropDownList2 " runat= "server ">
</asp:DropDownList>
</td>
</tr>
</table>

<script language= "javascript " type= "text/javascript ">
var groups=document.getElementById( " <%=DropDownList1.ClientID%> ").options.length
var group=new Array(groups)
for (i=0; i <groups; i++)
group[i]=new Array()

group[0][0]=new Option( "请选择 ", "0 ");
group[1][0]=new Option( "电冰箱 ", "1 ");group[1][1]=new Option( "洗衣机 ", "2 ");
group[2][0]=new Option( "方便面 ", "3 ");group[2][1]=new Option( "饼干 ", "4 ");

var temp = document.getElementById( " <%=DropDownList2.ClientID%> ")
function redirect(x)
{
for (m=temp.options.length-1;m> 0;m--)
temp.options[m]=null
for (i=0;i <group[x].length;i++)
{
temp.options[i]=new Option(group[x][i].text,group[x][i].value)
}
temp.options[0].selected=true
}
</script>

下面的是Test.ascx.cs文件
using System;
using System.Data;
using System.Configuration;
using System.Collections;
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;

public partial class Test : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ListItemCollection items = new ListItemCollection();
items.Add(new ListItem( "请选择 ", "0 "));
items.Add(new ListItem( "家用电器 ", "1 "));
items.Add(new ListItem( "食品 ", "2 "));

DropDownList1.DataSource = items;
DropDownList1.DataBind();
}
}

public int Select1
{
get { return int.Parse(DropDownList1.SelectedValue.ToString()); }
set { DropDownList1.SelectedValue = value.ToString(); }
}

public int Select2
{
get { return int.Parse(DropDownList2.SelectedValue.ToString()); }
set { DropDownList2.SelectedValue = value.ToString(); }
}
}


[解决办法]
1.你在select的onchange事件里把该控件改变了，所以不能通过回发验证
2.SelectedValue属性是只读的，不能赋值。你可以给SelectedIndex赋值
[解决办法]
在客户端添加的option服务器端并不能得到.
[解决办法]
呵呵,他回答了.没刷新,没看见