declare method in uc.ascx.cs
public event EventHandler<eventargs>Click;
public void Btn1_Click(object sender, System.EventArgs e)
{
try
{
this.Click(this.Btn1, e);
}
catch (Exception ex)
{
}
}
and Main thing is that
<asp:button id="btn1" runat="server" onclick="btn1_Click" />
write Button Onclick in design side