button inside updatepanel cause entire page to refresh

Question

I use two UpdatePanel tags, one has a Svg inside and I need to refresh its content when a button is clicked, and the button is inside another UpdatePanel. And I just realize my Page_Load function in codebehind gets executed everytime I click the button. I set the property UpdateMode="Conditional" already but not helping. Any idea why? Following is my code:

           <asp:ScriptManager ID="ScriptManager1" runat="server">
           </asp:ScriptManager>
           <asp:UpdatePanel runat="server" id="GlobalUpdatePanel" UpdateMode="Conditional">
              <Triggers>
                  <asp:AsyncPostBackTrigger controlid="ButtonPP" eventname="Click" />
              </Triggers>
              <ContentTemplate>
                  <svg width ="1024" height = "540"></svg>            
              </ContentTemplate>
           </asp:UpdatePanel>
           <asp:UpdatePanel ID="ControlUpdatePanel" runat="server" Visible="True" UpdateMode="Conditional">
              <ContentTemplate>      
                  <asp:Button id ="ButtonPP" runat="server" Text="Run PP"  OnClick="ButtonPP_Click" />
              </ContentTemplate>
           </asp:UpdatePanel> 

Thanks in advance!

Answer 1

Since the Page_Load function in code behind gets executed everytime the button is clicked, I'd guess you need to add if (!IsPostBack) in there, something like this:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        // code that's only executed at first load
    }
}