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IExtenderProviderService Interface

Provides an interface for adding and removing extender providers at design time.

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

'Declaration
Public Interface IExtenderProviderService
'Usage
Dim instance As IExtenderProviderService

Typically, only components that have been added to a container offer extender providers. The IExtenderProviderService allows you to extend this capability to objects that are not in the container.

The following example demosntrates using the IExtenderProviderService from a designer to add and remove an IExtenderProvider implementation.

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

' This designer adds a ComponentExtender extender provider,  
' and removes it when the designer is destroyed. 
Public Class ExtenderServiceDesigner
    Inherits System.Windows.Forms.Design.ControlDesigner

   ' A local reference to an obtained IExtenderProviderService. 
   Private localExtenderServiceReference As IExtenderProviderService
   ' An IExtenderProvider that this designer supplies. 
   Private extender As ComponentExtender   

   Public Sub New()
    End Sub 

    Public Overrides Sub Initialize(ByVal component As System.ComponentModel.IComponent)
        MyBase.Initialize(component)

        ' Attempts to obtain an IExtenderProviderService. 
        Dim extenderService As IExtenderProviderService = CType(component.Site.GetService(GetType(IExtenderProviderService)), IExtenderProviderService)
        If (extenderService IsNot Nothing) Then 
            ' If the service was obtained, adds a ComponentExtender  
            ' that adds an "ExtenderIndex" integer property to the  
            ' designer's component.
            extender = New ComponentExtender()
            extenderService.AddExtenderProvider(extender)
            localExtenderServiceReference = extenderService
        Else
            MessageBox.Show("Could not obtain an IExtenderProviderService.")
        End If 
    End Sub 

    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        ' Removes any previously added extender provider. 
        If (localExtenderServiceReference IsNot Nothing) Then
            localExtenderServiceReference.RemoveExtenderProvider(extender)
            localExtenderServiceReference = Nothing 
        End If 
    End Sub 
End Class 

' IExtenderProviderImplementation that adds an integer property  
' named "ExtenderIndex" to any design-mode document object.
<ProvidePropertyAttribute("ExtenderIndex", GetType(IComponent))> _
Public Class ComponentExtender
    Implements System.ComponentModel.IExtenderProvider

    ' Stores the value of the property to extend a component with. 
    Public index As Integer = 0

    Public Sub New()
    End Sub 

    ' Extends any type of object. 
    Public Function CanExtend(ByVal extendee As Object) As Boolean Implements IExtenderProvider.CanExtend
        Return True 
    End Function 

    Public Function GetExtenderIndex(ByVal component As IComponent) As Integer 
        Return index
    End Function 

    Public Sub SetExtenderIndex(ByVal component As IComponent, ByVal index As Integer)
        Me.index = index
    End Sub 
End Class 

' Example UserControl associated with the ExtenderServiceDesigner.
<DesignerAttribute(GetType(ExtenderServiceDesigner))> _
Public Class ExtenderServiceTestControl
    Inherits System.Windows.Forms.UserControl

    Public Sub New()
    End Sub 
End Class

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.

.NET Framework

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