Control.OnBubbleEvent Method (System.Web.UI)

OnBubbleEvent Method

.NET Framework Class Library

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)

Syntax

Visual Basic (Declaration)

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

Visual Basic (Usage)

Dim source As Object
Dim args As EventArgs
Dim returnValue As Boolean

returnValue = Me.OnBubbleEvent(source, _
    args)

protected virtual bool OnBubbleEvent(
    Object source,
    EventArgs args
)

Visual C++

protected:
virtual bool OnBubbleEvent(
    Object^ source, 
    EventArgs^ args
)

JScript

protected function OnBubbleEvent(
    source : Object, 
    args : EventArgs
) : 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.

Remarks

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.

Examples

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.

Visual Basic

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
 _

public class ParentControl : Control 
{
   [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
   protected override bool OnBubbleEvent(object sender, EventArgs e)
   {
      Context.Response.Write("<br><br>ParentControl's OnBubbleEvent called.");
      Context.Response.Write("<br>Source of event is: " + sender.ToString());
      return true;
   }
   [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
   protected override void Render( HtmlTextWriter myWriter)
   {
      myWriter.Write("ParentControl");
      RenderChildren(myWriter);
   }
}

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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, 3.0, 2.0, 1.1, 1.0

Reference

Control Class

Control Members

System.Web.UI Namespace

RaiseBubbleEvent