请教关于动态载入自定义控件的问题

[lwj119]

程序功能为在default.aspx载入menu.ascx,通过点击menu上的按钮载入content.ascx,点击content.ascx上的btn执行相应的方法.但是点击content.ascx上的btn后,程序回到default.aspx的初始状态而content.ascx上btn的相应事件并没有执行.如果直接在default.aspx页上LoadControl("Modules/content.ascx");btn事件就可以正常执行.请问为什么出现这种情况?
以下是程序的主要代码:
--------------default.aspx-----------------------------
namespace Demo
{
public class Default : System.Web.UI.Page
{
protected System.Web.UI.WebControls.PlaceHolder PlaceHolder1;

private void Page_Load(object sender, System.EventArgs e)
{
Menu menu = (Menu)LoadControl("Modules/Menu.ascx");
PlaceHolder1.Controls.Clear();
PlaceHolder1.Controls.Add(menu);
}
}
}
----------------------Menu.ascx-----------------------
namespace Demo.Modules
{
public class Menu : System.Web.UI.UserControl
{
protected System.Web.UI.WebControls.Button BtnMenu;

private void BtnMenu_Click(object sender, System.EventArgs e)
{
PlaceHolder p = (PlaceHolder)Page.FindControl("PlaceHolder1");
Content cont = (Content)LoadControl("Content.ascx");
p.Controls.Clear();
p.Controls.Add(cont);
}
}
}
-------------------------Content.ascx-------------------
namespace Demo.Modules
{
public class Content : System.Web.UI.UserControl
{
protected System.Web.UI.WebControls.Button BtnContent;
private void BtnContent_Click(object sender, System.EventArgs e)
{
Response.Write("BtnContent Clicked");
}
}
}

[saucer]

it is complicated, you page should remember to re-load the user control upon postback, but for now, look into

DynamicControlsPlaceholder - A placeholder that saves its child controls
http://www.denisbauer.com/ASPNETControls/DynamicControlsPlaceholder.aspx