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ComponentEventHandler Delegate

Represents the method that will handle the ComponentAdding, ComponentAdded, ComponentRemoving, and ComponentRemoved events raised for component-level events.

Namespace:  System.ComponentModel.Design
Assembly:  System (in System.dll)

<ComVisibleAttribute(True)> _
<HostProtectionAttribute(SecurityAction.LinkDemand, SharedState := True)> _
Public Delegate Sub ComponentEventHandler ( _
	sender As Object, _
	e As ComponentEventArgs _


Type: System.Object
The source of the event.
Type: System.ComponentModel.Design.ComponentEventArgs
A ComponentEventArgs that contains the event data.

When you create a ComponentEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates.


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following example demonstrates registering a ComponentEventHandler and handling the ComponentAdded, ComponentAdding, ComponentRemoved and ComponentRemoving events.

Public Sub LinkComponentEvent(ByVal changeService As IComponentChangeService)
    ' Registers an event handler for the ComponentAdded,
    ' ComponentAdding, ComponentRemoved, and ComponentRemoving events.
    AddHandler changeService.ComponentAdded, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentAdding, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentRemoved, AddressOf Me.OnComponentEvent
    AddHandler changeService.ComponentRemoving, AddressOf Me.OnComponentEvent
End Sub

Private Sub OnComponentEvent(ByVal sender As Object, ByVal e As ComponentEventArgs)
    ' Displays changed component information on the console.            
    If (e.Component.Site IsNot Nothing) Then
        Console.WriteLine(("Name of the component related to the event: " + e.Component.Site.Name))
    End If
End Sub

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.