Building COM Add-ins for Office Applications

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COM add-ins aren't difficult to create, but there are several steps involved. The following sections outline these steps.

What You Need

To create a COM add-in, you need either of the following:

• Visual Basic 5.0 or later

• Office 2000 Developer

Office 2000 Developer provides a template project, COM Add-In.vbp, for creating a COM add-in in Visual Basic 6.0. This template project is available in the ODETools\V9\Samples\OPG\Samples\CH11\VB_COM_AddIn subfolder on the Office 2000 Developer CD-ROM. The template project supplies the files you need to create a COM add-in, as well as the code that forms the basis of any add-in.

The COM Add-In.vbp provides you with the following:

• An add-in designer. An add-in designer is a component that helps you to create and register a COM add-in. You can modify an add-in designer to create your COM add-in and hook it into an application's user interface. For more information about add-in designers, see "Working with Add-in Designers" later in this chapter.

• A reference to the IDTExtensibility2 type library. The Visual Basic 6.0 template project sets a reference to this type library, contained in the file Msaddndr.dll. The IDTExtensibility2 library supplies the events you can use to run code when your add-in is connected to or disconnected from the hosting application.

Note   This chapter focuses on creating COM add-ins in Visual Basic 6.0. The process of creating COM add-ins in Visual Basic 5.0 or with Office 2000 Developer differs in several ways that may not be fully in this chapter. For more information about creating add-ins in Visual Basic 5.0, see the documentation for Visual Basic 5.0. For more information about creating COM add-ins with Office 2000 Developer, see .