Documentation for: ASP.NET Ajax Version 1.0

This documentation is for a previous version. For the current released version, see the ASP.NET Ajax documentation on MSDN.

 

 

 

 

 

 

 

Enabled Property

Gets or sets a value that indicates whether the Timer control initiates a postback to the server after the number of milliseconds specified in the Interval property has elapsed.

Syntax

CSharp

[CategoryAttribute("Behavior")]
[DefaultValueAttribute(true)]
public bool Enabled { get; set; }

VisualBasic

<CategoryAttribute("Behavior")> _
<DefaultValueAttribute(True)> _
Public Property Enabled As Boolean

ManagedCPlusPlus

[CategoryAttribute(L"Behavior")]
[DefaultValueAttribute(true)]
public:
bool Enabled {
	bool get ();
	void set (bool value);
}

JSharp

/** @property */
/** @property */

Value

Return Value

true if Timer will initiate a postback; otherwise, false. The default value is true.

Remarks

Use the Enabled property to turn the Timer control on and off. When you set Enabled to true, the Timer control starts its timer countdown when the Web page is rendered.

On postback, you can change property values in the Enabled property, and the changes will be reflected when the Web page content is rendered in the browser. If you change the Enabled property and then change it back to its original value within the same postback, the Timer control runs as if no change had been made.

Examples

The following example shows an UpdatePanel control that displays a randomly generated stock price and the time that the stock price was generated. By default, the Timer control updates the content in the UpdatePanel control every 10 seconds. The user can decide to update the stock price every 10 seconds, every 60 seconds, or not at all. When the user decides not to update the stock price, the Enabled property is set to false.

cs

<%@ Page Language="C#" AutoEventWireup="true" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Timer Example Page</title>
    <script runat="server">
        protected void Page_Load(object sender, EventArgs e)
        {
            OriginalTime.Text = DateTime.Now.ToLongTimeString();
        }

        protected void Timer1_Tick(object sender, EventArgs e)
        {
            StockPrice.Text = GetStockPrice();
            TimeOfPrice.Text = DateTime.Now.ToLongTimeString();
        }

        private string GetStockPrice()
        {
            double randomStockPrice = 50 + new Random().NextDouble();
            return randomStockPrice.ToString("C");
        }

        protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
        {
            Timer1.Enabled = true;
            Timer1.Interval = 10000;
        }

        protected void RadioButton2_CheckedChanged(object sender, EventArgs e)
        {
            Timer1.Enabled = true;
            Timer1.Interval = 60000;
        }

        protected void RadioButton3_CheckedChanged(object sender, EventArgs e)
        {
            Timer1.Enabled = false;
        }

</script>
</head>
<body>
    <form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server" />
        <asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="10000" />

        <asp:UpdatePanel ID="StockPricePanel" runat="server" UpdateMode="Conditional">
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Timer1" />
        </Triggers>
        <ContentTemplate>
            Stock price is <asp:Label id="StockPrice" runat="server"></asp:Label><BR />
            as of <asp:Label id="TimeOfPrice" runat="server"></asp:Label>  
            <br />

        </ContentTemplate>
        </asp:UpdatePanel>
        <div>
        <br />
        Update stock price every:<br />
        <asp:RadioButton ID="RadioButton1" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="10 seconds" OnCheckedChanged="RadioButton1_CheckedChanged" /><br />
        <asp:RadioButton ID="RadioButton2" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="60 seconds" OnCheckedChanged="RadioButton2_CheckedChanged" /><br />
        <asp:RadioButton ID="RadioButton3" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="Never" OnCheckedChanged="RadioButton3_CheckedChanged" />
        <br />
        Page loaded at <asp:Label ID="OriginalTime" runat="server"></asp:Label>
        </div>
    </form>
</body>
</html>

vb

<%@ Page Language="VB" AutoEventWireup="true" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Timer Example Page</title>
    <script runat="server">
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
            OriginalTime.Text = DateTime.Now.ToLongTimeString()
        End Sub

        Protected Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs)
            StockPrice.Text = GetStockPrice()
            TimeOfPrice.Text = DateTime.Now.ToLongTimeString()
        End Sub

        Private Function GetStockPrice() As String
            Dim randomStockPrice As Double = 50 + New Random().NextDouble()
            Return randomStockPrice.ToString("C")
        End Function

        Protected Sub RadioButton1_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
            Timer1.Interval = 10000
            Timer1.Enabled = True
        End Sub

        Protected Sub RadioButton2_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
            Timer1.Interval = 60000
            Timer1.Enabled = True
        End Sub

        Protected Sub RadioButton3_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
            Timer1.Enabled = False
        End Sub
</script>
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server" />
        <asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="10000" />

        <asp:UpdatePanel ID="StockPricePanel" runat="server" UpdateMode="Conditional">
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Timer1" />
        </Triggers>
        <ContentTemplate>
            Stock price is <asp:Label id="StockPrice" runat="server"></asp:Label><BR />
            as of <asp:Label id="TimeOfPrice" runat="server"></asp:Label>  
        </ContentTemplate>
        </asp:UpdatePanel>
        <div>
            <asp:RadioButton ID="RadioButton1" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="10 seconds" OnCheckedChanged="RadioButton1_CheckedChanged" /><br />
            <asp:RadioButton ID="RadioButton2" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="60 seconds" OnCheckedChanged="RadioButton2_CheckedChanged" /><br />
            <asp:RadioButton ID="RadioButton3" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="Never" OnCheckedChanged="RadioButton3_CheckedChanged" /><br />
            <br />
        Page originally created at <asp:Label ID="OriginalTime" runat="server"></asp:Label>
        </div>
    </form>
</body>
</html>

Assembly: System.Web.Extensions (Module: System.Web.Extensions)