计算机无法识别wd sub,错误：在当前上下文中不存在名称'lvSubCategories'

我想根据类别显示子类别我将Listview放在另一个ListView中，但内部Listview在名为'lvSubCategories'的cs文件中抛出一个错误，在当前情况下不存在。错误：在当前上下文中不存在名称'lvSubCategories'

listView可以不包含另一个listview本身内？

这里是我的Test.aspx标记：

runat="server" />

OnClick="btnLoadCategories_Click" />

这里是我的Test.aspx.cs代码：

using System;

using System.Collections.Generic;

using System.Configuration;

using System.Data;

using System.Data.SqlClient;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace ShoppingHeart

{

public partial class Test : System.Web.UI.Page

{

protected void btnLoadCategories_Click(object sender, EventArgs e)

{

var ds = new DataSet();

var ds1 = new DataSet();

string Categoryquery = "Select * from Category";

string SubCategoryquery = "Select SubCategoryName from SubCategory where CategoryId = 1003";

string ConString = ConfigurationManager.ConnectionStrings["MyCon"].ConnectionString.ToString();

using (var conn = new SqlConnection(ConString))

{

var adpt = new SqlDataAdapter(Categoryquery, conn);

adpt.Fill(ds);

lvCategories.DataSource = ds;

lvCategories.DataBind();

}

using (var conn = new SqlConnection(ConString))

{

var adpt = new SqlDataAdapter(SubCategoryquery, conn);

adpt.Fill(ds1);

lvSubCategories.DataSource = ds1;

lvSubCategories.DataBind();

}

}

}

}