asp.net如何为列表中的每一项添加数量选择器？

<asp:Repeater ID="rptItems" runat="server" OnItemDataBound="rptItems_ItemDataBound">
    <ItemTemplate>
        <div>
            <asp:Label ID="lblItemName" runat="server" Text='<%# Eval("ItemName") %>'></asp:Label>
            <asp:DropDownList ID="ddlQuantity" runat="server"></asp:DropDownList>
        </div>
    </ItemTemplate>
</asp:Repeater>
<asp:Button ID="btnSubmit" runat="server" Text="提交" OnClick="btnSubmit_Click" />

protected void rptItems_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DropDownList ddlQuantity = (DropDownList)e.Item.FindControl("ddlQuantity");
        for (int i = 1; i <= 10; i++)
        {
            ddlQuantity.Items.Add(new ListItem(i.ToString(), i.ToString()));
        }
    }
}

protected void btnSubmit_Click(object sender, EventArgs e)
{
    foreach (RepeaterItem item in rptItems.Items)
    {
        if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
        {
            Label lblItemName = (Label)item.FindControl("lblItemName");
            DropDownList ddlQuantity = (DropDownList)item.FindControl("ddlQuantity");
            
            string itemName = lblItemName.Text;
            int quantity = Convert.ToInt32(ddlQuantity.SelectedValue);
            
            // 处理每个选择器的值，例如保存到数据库或进行其他逻辑操作
        }
    }
}