title: Why is my asp .net updatePanel timer refreshing the entire page?
body: <p>I have a page which displays particular controls based on a set of checks in preload and load methods.</p>
  
  <p>I have an update panel in which should display the contents of a file whilst it is being written to. I do this by having a timer in the updatepanel and a textbox. The plan is to update the textbox with file contents on each tick of the timer.</p>
  
  <p>Now as far as i understand it from this; <a href="https://msdn.microsoft.com/en-us/library/cc295400.aspx" rel="nofollow">https://msdn.microsoft.com/en-us/library/cc295400.aspx</a> I should be able to just update the textbox in the updatepanel without a entire page refresh but i see my page_load being hit, why?</p>
  
  <p>My code</p>
  
  <pre><code>            &lt;asp:UpdatePanel ID="updatePnlStatusScreen" runat="server" Visible="False"&gt;
                  &lt;ContentTemplate&gt;
                      &lt;asp:Timer ID="timerLogFileOutput" runat="server" Enabled="False" Interval="5000" ontick="timerLogOutput_Tick"&gt;
                      &lt;/asp:Timer&gt;
                      &lt;asp:TextBox ID="tbLogOutputScreen" runat="server" Height="50%" Width="100%"&gt;Nothing logged yet...&lt;/asp:TextBox&gt;
                  &lt;/ContentTemplate&gt;
              &lt;/asp:UpdatePanel&gt;
  </code></pre>