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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)

public interface 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.

using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;

namespace ExtenderServiceExample
{    
    // This designer adds a ComponentExtender extender provider,  
    // and removes it when the designer is destroyed. 
    public class ExtenderServiceDesigner : 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()
        {
        }

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

            // Attempts to obtain an IExtenderProviderService.
            IExtenderProviderService extenderService = (IExtenderProviderService)component.Site.GetService(typeof(IExtenderProviderService));
            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.");
        }

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

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

        public ComponentExtender()
        {
        }

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

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

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

    // Example UserControl associated with the ExtenderServiceDesigner.
    [DesignerAttribute(typeof(ExtenderServiceDesigner))]
    public class ExtenderServiceTestControl : System.Windows.Forms.UserControl
    {		
        public ExtenderServiceTestControl()
        {						
        }
    }
}

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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