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Control.OnBubbleEvent Method

Determines whether the event for the server control is passed up the page's UI server control hierarchy.

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

'Declaration
Protected Overridable Function OnBubbleEvent ( _
	source As Object, _
	args As EventArgs _
) As Boolean

Parameters

source
Type: System.Object
The source of the event.
args
Type: System.EventArgs
An EventArgs object that contains the event data.

Return Value

Type: System.Boolean
true if the event has been canceled; otherwise, false. The default is false.

ASP.NET server controls such as the Repeater, DataList and GridView Web controls can contain child controls that raise events. For example, each row in a GridView control can contain one or more buttons created dynamically by templates. Rather than each button raising an event individually, events from the nested controls are "bubbled"—that is, they are sent to the naming container. The naming container in turn raises a generic event called RowCommand with parameter values. These values allow you to determine which individual control that raised the original event. By responding to this single event, you can avoid having to write individual event-handling methods for child controls.

The following example overrides the OnBubbleEvent method in a custom ASP.NET server control, ParentControl. This method is invoked when a child control of ParentControl calls the RaiseBubbleEvent method. When this happens, the ParentControl class writes two strings to the containing ASP.NET page, the first stating that its OnBubbleEvent method has been called, the second identifying the source control of the RaiseBubbleEvent method.


Public Class ParentControl
   Inherits Control

   <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
   Protected Overrides Function OnBubbleEvent(sender As Object, e As EventArgs) As Boolean
      Context.Response.Write("<br><br>ParentControl's OnBubbleEvent called.")
      Context.Response.Write(("<br>Source of event is: " + sender.ToString()))
      Return True
   End Function 'OnBubbleEvent

   <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
   Protected Overrides Sub Render(myWriter As HtmlTextWriter)
      myWriter.Write("ParentControl")
      RenderChildren(myWriter)
   End Sub 'Render
End Class 'ParentControl
 _


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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