Timer.Interval Property (System.Web.UI)

Interval Property

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

Microsoft Visual Studio 2010/.NET Framework 4.0

.NET Framework Class Library

Timer..::.Interval Property

Gets or sets the number of milliseconds to wait before initiating a postback.

Namespace: System.Web.UI
Assembly: System.Web.Extensions (in System.Web.Extensions.dll)

Syntax

Visual Basic (Declaration)

Public Property Interval As Integer

Visual Basic (Usage)

Dim instance As Timer
Dim value As Integer

value = instance.Interval

instance.Interval = value

public int Interval { get; set; }

Visual C++

public:
property int Interval {
    int get ();
    void set (int value);
}

JScript

public function get Interval () : int
public function set Interval (value : int)

ASP.NET

<asp:Timer Interval="Int32" />

Property Value

Type: System..::.Int32
The number of milliseconds to wait before initiating a postback. The default value is 60,000 (60 seconds).

Exceptions

Exception	Condition
ArgumentOutOfRangeException	The specified value is less than or equal to zero.

Remarks

Use the Interval property to set how often the Timer control initiates a postback to the server. You can change the value of the Interval property in server code after a postback, such as in an event handler for the Tick event. The accuracy of when the Timer control posts back to the Web server depends on the accuracy of the ECMAScript (JavaScript) window.setTimeout function that runs in the browser.

Note:
Setting the Interval property to a small value can generate significant traffic to and from the Web server. Use the Timer control to refresh the content only as often as necessary.

When you change the value of the Interval property, the ECMAScript timing code running in the browser will be reset when the updates are rendered.

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. The Interval property is set to the user's choice.

Visual Basic

<%@ 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  >
<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>

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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html >
<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>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5

Reference

Timer Class

Timer Members

System.Web.UI Namespace