ASP.NET更新标签分别和异步

Question

Ok so I can successfully update my page labels asynchronously using a timer. The problem is that the labels always update simultaneously while I want each one to update in sequence.

Here is my aspx:

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
 <asp:UpdatePanel runat="server" id="UpdatePanel1" 
  UpdateMode="Conditional">
  <contenttemplate>
     <asp:Timer id="Timer1" runat="server"
        Interval="5000" 
        OnTick="Timer1_Tick">
     </asp:Timer>
     <asp:Label ID="Label1" runat="server" >Label1</asp:Label>
     <asp:Label ID="Label2" runat="server" >Label2</asp:Label>
  </contenttemplate>
</asp:UpdatePanel>
</asp:Content>

And my codebehind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;

public partial class _Default : Page
{

 public int counter = 0;

protected void Timer1_Tick(object sender, EventArgs e)
{
    counter++;
    System.Diagnostics.Debug.WriteLine("Counter: " + counter);
    if (counter == 1)
    {
        Label1.Text = "<font color='green'>Started</font>";
        UpdatePanel1.Update();

    }
    if (counter == 2)
    {
        Label2.Text = "<font color='green'>Started</font>";
        UpdatePanel1.Update();

    }

}
}

After trying several examples I decided to ask here and see if I was missing something obvious. Somehow my counter variable is being reset to 0 which tells me that the entire page may be being rerun each tick instead of just the Timer1_Tick method.

Answer 1

The clause where counter == 1 also increments counter , so by the end of the clause, counter = 2, hence the other condition is also true.

Don't increment counter within the counter == 1 clause.