带中继器的Ajax Modal Popup Extender

// ASPX页面示例
<asp:Repeater ID="rptItems" runat="server" OnItemCommand="rptItems_ItemCommand">
    <ItemTemplate>
        <asp:LinkButton ID="lnkDetail" runat="server" 
            CommandName="ShowDetail" 
            CommandArgument='<%# Eval("ID") %>'
            Text='<%# Eval("Title") %>' />
    </ItemTemplate>
</asp:Repeater>

<asp:Panel ID="pnlModal" runat="server" Style="display:none">
    <h3><asp:Literal ID="litTitle" runat="server" /></h3>
    <p><asp:Literal ID="litContent" runat="server" /></p>
    <asp:Button ID="btnClose" runat="server" Text="关闭" />
</asp:Panel>

<ajaxToolkit:ModalPopupExtender ID="mpeDetail" runat="server"
    TargetControlID="dummyButton"
    PopupControlID="pnlModal"
    CancelControlID="btnClose"
    BackgroundCssClass="modalBackground" />

// 后台代码
protected void rptItems_ItemCommand(object source, RepeaterCommandEventArgs e)
{
    if (e.CommandName == "ShowDetail")
    {
        var itemId = Convert.ToInt32(e.CommandArgument);
        var data = GetItemDetail(itemId);
        
        litTitle.Text = data.Title;
        litContent.Text = data.Description;
        
        mpeDetail.Show();
    }
}

.modalBackground {
    background-color: Gray;
    opacity: 0.7;
}