通过单击按钮将项目添加到自定义用户控件

Question

以下是我的自定义用户控件UC_UserControl.ascx的代码示例

<%@ Control Language="vb" AutoEventWireup="false" CodeBehind="UC_UserControl.ascx.vb" Inherits="WebApplication1.UC_ComboControl" %>
<div id="divMain">
<fieldset id="fsControls">
    <legend id="lgd1" title="My Field Set">My Field Set</legend>
   <asp:Panel ID="pnlMain" runat="server">
        <asp:Panel ID="Panel1" runat="server">
            <span>Code</span>
            <asp:DropDownList ID="ddlCode" runat="server"> 
            </asp:DropDownList>
        </asp:Panel>
        <asp:Panel ID="Panel2" runat="server">
                <asp:DropDownList ID="ddlCcyCode" runat="server"> 
                </asp:DropDownList>
                <asp:TextBox ID="txtAmount" runat="server" />
        </asp:Panel>
        <asp:Panel ID="Panel3" runat="server">
            <span>Narrative</span>
            <asp:TextBox ID="txtNarrative" runat="server" />
        </asp:Panel>
</asp:Panel>
</fieldset>
<br /><br />
</div>
<input type="submit" name="Submit" value="+" id="btnSubmit" onclick="Add()"/>

当我单击提交按钮时，我想在同一个自定义控件中重复附加相同的项目集。请帮我解决这个问题。