UpdatePanel控件(四)——Timer控件(2)

Timer控件更典型的应用是：定时刷新UpdatePanel控件的内容。

前台：

    <div>
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <asp:Timer ID="Timer1" runat="server" Interval="1000">
                </asp:Timer>
                <asp:Label ID="Label2" runat="server" Text="The time is:"></asp:Label>
                <%= DateTime.Now.ToString("T") %><br />
            </ContentTemplate>
        </asp:UpdatePanel>
        <br />
        <fieldset>
            <legend>
                <asp:UpdatePanel ID="up1" runat="server">
                    <Triggers>
                        <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
                    </Triggers>
                    <ContentTemplate>
                        <asp:Label ID="lblQuote" runat="server" Text="The time is:"></asp:Label>
                    </ContentTemplate>
                </asp:UpdatePanel>
            </legend>
        </fieldset>
    </div>

 

后台：

    protected void Page_Load(object sender, EventArgs e)
    {
        List<string> quotes = new List<string>();
        quotes.Add("A fool and his money are soon parted");
        quotes.Add("A penny saved is a penny earned");
        quotes.Add("An apple a day keeps the doctor away");

        Random rnd = new Random();
        lblQuote.Text = quotes[rnd.Next(quotes.Count)];
    }

 

注：Timer控件每隔5秒刷新一次某论坛的信息。如果开着浏览器窗口，即使你去做别的事情，浏览器也能显示最新的信息，因为论坛上的其他人回传了这些内容。