不能在中继器中找到我的文本框

我正在为一家咖啡馆制作菜单。它显示了食品和饮料，价格，然后我想要一个文本框，人们可以在这里写下他们想买多少，显示在一个文本框中。然后，我希望每个文本框都有一个基于菜单项ID的唯一ID。

这是我的中继器:

<asp:Repeater ID="ParentRepeater" runat="server" OnItemDataBound="ParentRepeater_ItemDataBound">
        <ItemTemplate>
            <h2>
                <%#DataBinder.Eval(Container.DataItem, "typenavn") %></h2>
            <asp:HiddenField ID="HiddenField1" Value='<%# Eval("id") %>' runat="server" />
            <asp:Repeater ID="ChildRepeater" runat="server">
                <ItemTemplate>
                    <table>
                        <tr>
                            <td style="width: 400px">
                                <%#DataBinder.Eval(Container.DataItem, "productName") %>
                            </td>
                            <td style="width: 400px">
                                <%#DataBinder.Eval(Container.DataItem, "pris") %>
                            </td>
                            <td>
                                <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
                            </td>
                        </tr>
                    </table>
                </ItemTemplate>
            </asp:Repeater>
        </ItemTemplate>
    </asp:Repeater>

下面是我的代码:

protected void ParentRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        RepeaterItem item = e.Item;
        if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
        {
            Repeater ChildRepeater = (Repeater)item.FindControl("ChildRepeater");
            HiddenField hide = e.Item.FindControl("HiddenField1") as HiddenField;
            int id = Convert.ToInt32(hide.Value);
            var query = from es in gr.products
                        where es.typeID == id
                        select es;
            List<product> list = new List<product>();
            foreach (product pro in query)
            {
                list.Add(pro);
            }
            ChildRepeater.DataSource = list;
            ChildRepeater.DataBind();
            int h = 0;
            foreach (RepeaterItem item1 in ChildRepeater.Items)
            {
                if (item1.ItemType == ListItemType.Item || item1.ItemType == ListItemType.AlternatingItem)
                {
                    TextBox txt = (TextBox)item1.FindControl("TextBox1") as TextBox;
                    HiddenField hf = (HiddenField)item1.FindControl("HiddenField2") as HiddenField;
                    for (int i = 0; i < list.Count; i++)
                    {
                        txt.ID = "HB" + list[h].id.ToString();
                        hf.Value = list[h].id.ToString();
                        h++;
                        break;
                    }
                }
            }
        }
    }

有谁知道如何找到文本框吗??

foreach(RepeaterItem item in ChildRepeater.Items){
  if(item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem){
    var txt = (TextBox)item.FindControl("TextBox1");
  }
}