asp.net中Timer定时器在web中无刷新的使用

<form id="form1" runat="server"> 
    <div>
    <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
      <asp:UpdatePanel ID="UpdatePanel1" runat="server">
      <ContentTemplate>
        <asp:Timer ID="Timer1" runat="server" Interval="1000" ontick="Timer1_Tick">
        </asp:Timer>
         update中的：<asp:Label  ID="Label2" runat="server" Text=""></asp:Label>
      </ContentTemplate>
           </asp:UpdatePanel>
        当前秒：<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
    </div>
   </form>

 protected void Page_Load(object sender, EventArgs e)
        {
           
        }
        protected void Timer1_Tick(object sender, EventArgs e)
        {
            //这里可以操作你想做的事情，比如定时查询数据库
            Label1.Text = DateTime.Now.ToLongTimeString()+":"+DateTime.Now.Millisecond;
            Label2.Text = DateTime.Now.ToLongTimeString() + ":" + DateTime.Now.Millisecond;
        }