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

public interface IExtenderProviderService
public interface IExtenderProviderService
Not applicable.

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

package ExtenderServiceExample;
import System.*;
import System.Collections.*;
import System.ComponentModel.*;
import System.ComponentModel.Design.*;
import System.Windows.Forms.*;
import System.Windows.Forms.Design.*;

// This designer adds a ComponentExtender extender provider, 
// and removes it when the designer is destroyed.
public class ExtenderServiceDesigner extends 
    System.Windows.Forms.Design.ControlDesigner
{
    // A local reference to an obtained IExtenderProviderService.
    private IExtenderProviderService localExtenderServiceReference;

    // An IExtenderProvider that this designer supplies.
    private ComponentExtender extender;

    public ExtenderServiceDesigner()
    {
    } //ExtenderServiceDesigner

    public void Initialize(System.ComponentModel.IComponent component)
    {
        super.Initialize(component);

        // Attempts to obtain an IExtenderProviderService.
        IExtenderProviderService extenderService = (IExtenderProviderService)
            component.get_Site().GetService(IExtenderProviderService.class.
            ToType());
        if (extenderService != null) {
            // 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.");
        }
    } //Initialize

    protected void Dispose(boolean disposing)
    {
        // Removes any previously added extender provider.
        if (localExtenderServiceReference != null) {
            localExtenderServiceReference.RemoveExtenderProvider(extender);
            localExtenderServiceReference = null;
        }
    } //Dispose
} //ExtenderServiceDesigner

// IExtenderProviderImplementation that adds an integer property 
// named "ExtenderIndex" to any design-mode document object.
/** @ attribute ProvidePropertyAttribute("ExtenderIndex", 
    IComponent.class.ToType())
 */
public class ComponentExtender implements 
    System.ComponentModel.IExtenderProvider
{
    // Stores the value of the property to extend a component with.
    public int index = 0;

    public ComponentExtender()
    {
    } //ComponentExtender

    public boolean CanExtend(Object extendee)
    {
        // Extends any type of object.
        return true;
    } //CanExtend

    public int GetExtenderIndex(IComponent component)
    {
        return index;
    } //GetExtenderIndex

    public void SetExtenderIndex(IComponent component, int index)
    {
        this.index = index;
    } //SetExtenderIndex
} //ComponentExtender

// Example UserControl associated with the ExtenderServiceDesigner.
/** @ attribute DesignerAttribute(ExtenderServiceDesigner.class.ToType())
 */
public class ExtenderServiceTestControl extends 
    System.Windows.Forms.UserControl
{
    public ExtenderServiceTestControl()
    {
    } //ExtenderServiceTestControl
} //ExtenderServiceTestControl

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

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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