计时器时钟周期事件未触发

<asp:Timer ID="timer1" runat="server" OnTick="timer1_tick">                                        </asp:Timer>
<asp:UpdatePanel ID="updatepanel1" runat="server" UpdateMode="Conditional">
  <ContentTemplate>
     <asp:Label ID="lbltimer" runat="server"></asp:Label>
  </ContentTemplate>
  <Triggers>
     <asp:AsyncPostBackTrigger ControlID="timer1" EventName="tick" />
  </Triggers>
</asp:UpdatePanel>

在页面加载中编码！回发

        timer1.Enabled = true;
        Session["timeout"] = DateTime.Now.AddMinutes(60).ToString();

这是即时报价事件编码。问题是每当我运行应用程序时，tick 事件根本不会触发。该应用程序 Asp.net 应用程序。

protected void timer1_tick(object sender, EventArgs e)
{
    if (0 > DateTime.Compare(DateTime.Now,
       DateTime.Parse(Session["timeout"].ToString())))
    {
        int hrs = (((Int32)DateTime.Parse(Session["timeout"].
        ToString()).Subtract(DateTime.Now).TotalMinutes)) / 60;
        int mins = (((Int32)DateTime.Parse(Session["timeout"].
        ToString()).Subtract(DateTime.Now).TotalMinutes)) % 60;
        int seconds = (((Int32)DateTime.Parse(Session["timeout"].
        ToString()).Subtract(DateTime.Now).TotalSeconds)) % 60;

        lbltimer.Text = "Time left is " + hrs.ToString() + " : " + mins.ToString() + " : " + seconds.ToString();
        if (mins == 1 && seconds == 0 && hrs == 0)
        {
            lbltimer.Text = "Please submit test 1min left";
        }
        else if (hrs == 0 && mins == 0 && seconds == 0)
        {
            lbltimer.Text = "Test Time Over";
        }
    }
}