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Timer Class

Performs asynchronous or synchronous Web page postbacks at a defined interval.

Namespace:  System.Web.UI
Assembly:  System.Web.Extensions (in System.Web.Extensions.dll)
public class Timer : Control, IPostBackEventHandler, 
	IScriptControl
<asp:Timer />

The Timer type exposes the following members.

  NameDescription
Public methodTimerInitializes a new instance of the Timer class.
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  NameDescription
Protected propertyAdapterGets the browser-specific adapter for the control. (Inherited from Control.)
Public propertyAppRelativeTemplateSourceDirectoryGets or sets the application-relative virtual directory of the Page or UserControl object that contains this control. (Inherited from Control.)
Public propertyBindingContainerInfrastructure. Gets the control that contains this control's data binding. (Inherited from Control.)
Protected propertyChildControlsCreatedGets a value that indicates whether the server control's child controls have been created. (Inherited from Control.)
Public propertyClientIDGets the control ID for HTML markup that is generated by ASP.NET. (Inherited from Control.)
Public propertyClientIDModeGets or sets the algorithm that is used to generate the value of the ClientID property. (Inherited from Control.)
Protected propertyClientIDSeparatorGets a character value representing the separator character used in the ClientID property. (Inherited from Control.)
Protected propertyContextGets the HttpContext object associated with the server control for the current Web request. (Inherited from Control.)
Public propertyControlsGets a ControlCollection object that represents the child controls for a specified server control in the UI hierarchy. (Inherited from Control.)
Public propertyDataItemContainerGets a reference to the naming container if the naming container implements IDataItemContainer. (Inherited from Control.)
Public propertyDataKeysContainerGets a reference to the naming container if the naming container implements IDataKeysControl. (Inherited from Control.)
Protected propertyDesignModeGets a value indicating whether a control is being used on a design surface. (Inherited from Control.)
Public propertyEnabledGets 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.
Public propertyEnableThemingGets or sets a value indicating whether themes apply to this control. (Inherited from Control.)
Public propertyEnableViewStateGets or sets a value indicating whether the server control persists its view state, and the view state of any child controls it contains, to the requesting client. (Inherited from Control.)
Protected propertyEventsGets a list of event handler delegates for the control. This property is read-only. (Inherited from Control.)
Protected propertyHasChildViewStateGets a value indicating whether the current server control's child controls have any saved view-state settings. (Inherited from Control.)
Public propertyIDGets or sets the programmatic identifier assigned to the server control. (Inherited from Control.)
Protected propertyIdSeparatorInfrastructure. Gets the character used to separate control identifiers. (Inherited from Control.)
Public propertyIntervalGets or sets the number of milliseconds to wait before initiating a postback.
Protected propertyIsChildControlStateClearedGets a value indicating whether controls contained within this control have control state. (Inherited from Control.)
Protected propertyIsTrackingViewStateGets a value that indicates whether the server control is saving changes to its view state. (Inherited from Control.)
Protected propertyIsViewStateEnabledGets a value indicating whether view state is enabled for this control. (Inherited from Control.)
Protected propertyLoadViewStateByIDGets a value indicating whether the control participates in loading its view state by ID instead of index. (Inherited from Control.)
Public propertyNamingContainerGets a reference to the server control's naming container, which creates a unique namespace for differentiating between server controls with the same Control.ID property value. (Inherited from Control.)
Public propertyPageGets a reference to the Page instance that contains the server control. (Inherited from Control.)
Public propertyParentGets a reference to the server control's parent control in the page control hierarchy. (Inherited from Control.)
Public propertyRenderingCompatibilityGets a value that specifies the ASP.NET version that rendered HTML will be compatible with. (Inherited from Control.)
Public propertySiteGets information about the container that hosts the current control when rendered on a design surface. (Inherited from Control.)
Public propertySkinIDGets or sets the skin to apply to the control. (Inherited from Control.)
Public propertyTemplateControlGets or sets a reference to the template that contains this control. (Inherited from Control.)
Public propertyTemplateSourceDirectoryGets the virtual directory of the Page or UserControl that contains the current server control. (Inherited from Control.)
Public propertyUniqueIDGets the unique, hierarchically qualified identifier for the server control. (Inherited from Control.)
Public propertyValidateRequestModeGets or sets a value that indicates whether the control checks client input from the browser for potentially dangerous values. (Inherited from Control.)
Protected propertyViewStateGets a dictionary of state information that allows you to save and restore the view state of a server control across multiple requests for the same page. (Inherited from Control.)
Protected propertyViewStateIgnoresCaseGets a value that indicates whether the StateBag object is case-insensitive. (Inherited from Control.)
Public propertyViewStateModeGets or sets the view-state mode of this control. (Inherited from Control.)
Public propertyVisibleOverrides the Visible property of the Control class to prevent this value from being set. (Overrides Control.Visible.)
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  NameDescription
Protected methodAddedControlCalled after a child control is added to the Controls collection of the Control object. (Inherited from Control.)
Protected methodAddParsedSubObjectNotifies the server control that an element, either XML or HTML, was parsed, and adds the element to the server control's ControlCollection object. (Inherited from Control.)
Public methodApplyStyleSheetSkinApplies the style properties defined in the page style sheet to the control. (Inherited from Control.)
Protected methodBeginRenderTracingBegins design-time tracing of rendering data. (Inherited from Control.)
Protected methodBuildProfileTreeInfrastructure. Gathers information about the server control and delivers it to the Trace property to be displayed when tracing is enabled for the page. (Inherited from Control.)
Protected methodClearCachedClientIDInfrastructure. Sets the cached ClientID value to null. (Inherited from Control.)
Protected methodClearChildControlStateDeletes the control-state information for the server control's child controls. (Inherited from Control.)
Protected methodClearChildStateDeletes the view-state and control-state information for all the server control's child controls. (Inherited from Control.)
Protected methodClearChildViewStateDeletes the view-state information for all the server control's child controls. (Inherited from Control.)
Protected methodClearEffectiveClientIDModeInfrastructure. Sets the ClientIDMode property of the current control instance and of any child controls to Inherit. (Inherited from Control.)
Protected methodCreateChildControlsCalled by the ASP.NET page framework to notify server controls that use composition-based implementation to create any child controls they contain in preparation for posting back or rendering. (Inherited from Control.)
Protected methodCreateControlCollectionCreates a new ControlCollection object to hold the child controls (both literal and server) of the server control. (Inherited from Control.)
Public methodDataBind()Binds a data source to the invoked server control and all its child controls. (Inherited from Control.)
Protected methodDataBind(Boolean)Binds a data source to the invoked server control and all its child controls with an option to raise the DataBinding event. (Inherited from Control.)
Protected methodDataBindChildrenBinds a data source to the server control's child controls. (Inherited from Control.)
Public methodDisposeEnables a server control to perform final clean up before it is released from memory. (Inherited from Control.)
Protected methodEndRenderTracingEnds design-time tracing of rendering data. (Inherited from Control.)
Protected methodEnsureChildControlsDetermines whether the server control contains child controls. If it does not, it creates child controls. (Inherited from Control.)
Protected methodEnsureIDCreates an identifier for controls that do not have an identifier assigned. (Inherited from Control.)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodFindControl(String)Searches the current naming container for a server control with the specified id parameter. (Inherited from Control.)
Protected methodFindControl(String, Int32)Infrastructure. Searches the current naming container for a server control with the specified id and an integer, specified in the pathOffset parameter, which aids in the search. You should not override this version of the FindControl method. (Inherited from Control.)
Public methodFocusSets input focus to a control. (Inherited from Control.)
Protected methodGetDesignModeStateInfrastructure. Gets design-time data for a control. (Inherited from Control.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetRouteUrl(Object)Gets the URL that corresponds to a set of route parameters. (Inherited from Control.)
Public methodGetRouteUrl(RouteValueDictionary)Gets the URL that corresponds to a set of route parameters. (Inherited from Control.)
Public methodGetRouteUrl(String, Object)Gets the URL that corresponds to a set of route parameters and a route name. (Inherited from Control.)
Public methodGetRouteUrl(String, RouteValueDictionary)Gets the URL that corresponds to a set of route parameters and a route name. (Inherited from Control.)
Protected methodGetScriptDescriptorsRetrieves properties from a Timer object that are passed to the client component that implements timer logic in the browser.
Protected methodGetScriptReferencesRetrieves the client script for the Timer control.
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodGetUniqueIDRelativeToReturns the prefixed portion of the UniqueID property of the specified control. (Inherited from Control.)
Public methodHasControlsDetermines if the server control contains any child controls. (Inherited from Control.)
Protected methodHasEventsReturns a value indicating whether events are registered for the control or any child controls. (Inherited from Control.)
Protected methodIsLiteralContentInfrastructure. Determines if the server control holds only literal content. (Inherited from Control.)
Protected methodLoadControlStateRestores control-state information from a previous page request that was saved by the SaveControlState method. (Inherited from Control.)
Protected methodLoadViewStateRestores view-state information from a previous page request that was saved by the SaveViewState method. (Inherited from Control.)
Protected methodMapPathSecureRetrieves the physical path that a virtual path, either absolute or relative, maps to. (Inherited from Control.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodOnBubbleEventDetermines whether the event for the server control is passed up the page's UI server control hierarchy. (Inherited from Control.)
Protected methodOnDataBindingRaises the DataBinding event. (Inherited from Control.)
Protected methodOnInitRaises the Init event. (Inherited from Control.)
Protected methodOnLoadRaises the Load event. (Inherited from Control.)
Protected methodOnPreRenderRaises the PreRender event of the Timer control. (Overrides Control.OnPreRender(EventArgs).)
Protected methodOnTickRaises the Tick event of the Timer control.
Protected methodOnUnloadRaises the Unload event. (Inherited from Control.)
Protected methodOpenFileGets a Stream used to read a file. (Inherited from Control.)
Protected methodRaiseBubbleEventAssigns any sources of the event and its information to the control's parent. (Inherited from Control.)
Protected methodRaisePostBackEventEnables a Timer control to raise the Tick event when a page is posted to the server.
Protected methodRemovedControlCalled after a child control is removed from the Controls collection of the Control object. (Inherited from Control.)
Protected methodRenderRenders the Timer control content to the browser by using the specified HtmlTextWriter object. (Overrides Control.Render(HtmlTextWriter).)
Protected methodRenderChildrenOutputs the content of a server control's children to a provided HtmlTextWriter object, which writes the content to be rendered on the client. (Inherited from Control.)
Public methodRenderControl(HtmlTextWriter)Outputs server control content to a provided HtmlTextWriter object and stores tracing information about the control if tracing is enabled. (Inherited from Control.)
Protected methodRenderControl(HtmlTextWriter, ControlAdapter)Outputs server control content to a provided HtmlTextWriter object using a provided ControlAdapter object. (Inherited from Control.)
Protected methodResolveAdapterGets the control adapter responsible for rendering the specified control. (Inherited from Control.)
Public methodResolveClientUrlGets a URL that can be used by the browser. (Inherited from Control.)
Public methodResolveUrlConverts a URL into one that is usable on the requesting client. (Inherited from Control.)
Protected methodSaveControlStateSaves any server control state changes that have occurred since the time the page was posted back to the server. (Inherited from Control.)
Protected methodSaveViewStateSaves any server control view-state changes that have occurred since the time the page was posted back to the server. (Inherited from Control.)
Protected methodSetDesignModeStateSets design-time data for a control. (Inherited from Control.)
Public methodSetRenderMethodDelegateInfrastructure. Assigns an event handler delegate to render the server control and its content into its parent control. (Inherited from Control.)
Public methodSetTraceData(Object, Object)Sets trace data for design-time tracing of rendering data, using the trace data key and the trace data value. (Inherited from Control.)
Public methodSetTraceData(Object, Object, Object)Sets trace data for design-time tracing of rendering data, using the traced object, the trace data key, and the trace data value. (Inherited from Control.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Protected methodTrackViewStateCauses tracking of view-state changes to the server control so they can be stored in the server control's StateBag object. This object is accessible through the Control.ViewState property. (Inherited from Control.)
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  NameDescription
Public eventDataBindingOccurs when the server control binds to a data source. (Inherited from Control.)
Public eventDisposedOccurs when a server control is released from memory, which is the last stage of the server control lifecycle when an ASP.NET page is requested. (Inherited from Control.)
Public eventInitOccurs when the server control is initialized, which is the first step in its lifecycle. (Inherited from Control.)
Public eventLoadOccurs when the server control is loaded into the Page object. (Inherited from Control.)
Public eventPreRenderOccurs after the Control object is loaded but prior to rendering. (Inherited from Control.)
Public eventTickOccurs when the number of milliseconds specified in the Interval property has elapsed and the page is posted to the server.
Public eventUnloadOccurs when the server control is unloaded from memory. (Inherited from Control.)
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  NameDescription
Public Extension MethodFindDataSourceControlReturns the data source that is associated with the data control for the specified control. (Defined by DynamicDataExtensions.)
Public Extension MethodFindFieldTemplateReturns the field template for the specified column in the specified control's naming container. (Defined by DynamicDataExtensions.)
Public Extension MethodFindMetaTableReturns the metatable object for the containing data control. (Defined by DynamicDataExtensions.)
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  NameDescription
Explicit interface implemetationPrivate propertyIControlBuilderAccessor.ControlBuilderFor a description of this member, see IControlBuilderAccessor.ControlBuilder. (Inherited from Control.)
Explicit interface implemetationPrivate methodIControlDesignerAccessor.GetDesignModeStateFor a description of this member, see IControlDesignerAccessor.GetDesignModeState. (Inherited from Control.)
Explicit interface implemetationPrivate methodIControlDesignerAccessor.SetDesignModeStateFor a description of this member, see IControlDesignerAccessor.SetDesignModeState. (Inherited from Control.)
Explicit interface implemetationPrivate methodIControlDesignerAccessor.SetOwnerControlInfrastructure. For a description of this member, see IControlDesignerAccessor.SetOwnerControl. (Inherited from Control.)
Explicit interface implemetationPrivate propertyIControlDesignerAccessor.UserDataFor a description of this member, see IControlDesignerAccessor.UserData. (Inherited from Control.)
Explicit interface implemetationPrivate propertyIDataBindingsAccessor.DataBindingsFor a description of this member, see IDataBindingsAccessor.DataBindings. (Inherited from Control.)
Explicit interface implemetationPrivate propertyIDataBindingsAccessor.HasDataBindingsFor a description of this member, see IDataBindingsAccessor.HasDataBindings. (Inherited from Control.)
Explicit interface implemetationPrivate propertyIExpressionsAccessor.ExpressionsFor a description of this member, see IExpressionsAccessor.Expressions. (Inherited from Control.)
Explicit interface implemetationPrivate propertyIExpressionsAccessor.HasExpressionsFor a description of this member, see IExpressionsAccessor.HasExpressions. (Inherited from Control.)
Explicit interface implemetationPrivate methodIParserAccessor.AddParsedSubObjectFor a description of this member, see IParserAccessor.AddParsedSubObject. (Inherited from Control.)
Explicit interface implemetationPrivate methodIPostBackEventHandler.RaisePostBackEventRaises the Tick event when a page is posted to the server.
Explicit interface implemetationPrivate methodIScriptControl.GetScriptDescriptorsRetrieves properties from a Timer object that are passed to the client component.
Explicit interface implemetationPrivate methodIScriptControl.GetScriptReferencesRetrieves the client script for the Timer control.
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In this topic:

Introduction

The Timer control enables you to perform postbacks at a specified interval. When you use the Timer control as a trigger for an UpdatePanel control, the UpdatePanel control is updated by using an asynchronous, partial-page update. You must include a ScriptManager object in a Web page to use the Timer control.

You use the Timer control to update an UpdatePanel control by including the timer inside the UpdatePanel control. Alternatively, you can place the timer outside the UpdatePanel control and set the timer as a trigger.

You can also initiate full postback of a complete Web page by including the Timer control in the Web page and not setting it as a trigger for an UpdatePanel control.

You can run server code when the timer interval has elapsed by creating an event handler for the Tick event. In the event handler, you can include code that dynamically adjusts the behavior of the Timer control.

Set the Interval property to specify how often postbacks will occur. Set the Enabled property to turn the Timer on or off.

NoteNote

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 is running in the browser.

The Interval property is defined in milliseconds. You must set the Interval property to a value that lets at least one asynchronous postback complete before the next postback is initiated. When the Timer control is outside an UpdatePanel control, the timer continues to run while the content of the UpdatePanel control is refreshed. If a new postback is initiated while an earlier postback is being processed, the first postback will be canceled. The default value is 60,000 milliseconds (60 seconds).

NoteNote

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

Declarative Syntax

<asp:Timer
    Enabled="True|False"
    EnableTheming="True|False"
    EnableViewState="True|False"
    ID="string"
    Interval="integer"
    OnDataBinding="DataBinding event handler"
    OnDisposed="Disposed event handler"
    OnInit="Init event handler"
    OnLoad="Load event handler"
    OnPreRender="PreRender event handler"
    OnTick="Tick event handler"
    OnUnload="Unload handler"
    runat="server"
    SkinID="string"
    Visible="True|False"
/>

The following example shows an UpdatePanel control that displays a randomly generated stock price and the time that the stock price was generated. The Timer control updates the content in the UpdatePanel control every 10 seconds.

NoteNote

In this example, the timer interval is set to 10 seconds so that when you run the example, you do not have to wait a long time to see the results. Because each timer interval causes a postback that causes network traffic, in a production application you should set the interval to the longest time that is still practical for your application.

<%@ 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 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");
        }
    </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>
        Page originally created at <asp:Label ID="OriginalTime" runat="server"></asp:Label>
        </div>
    </form>
</body>
</html>

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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