| Microsoft Office 2000/Visual Basic Programmer's Guide | |
Every Office application supports a new add-in architecture that allows developers to create a single add-in that can run in any application. This new add-in model is open to VBA developers and, because it is based on the Component Object Model (COM), it is also available to developers who are using Microsoft Visual Basic versions 5.0 and 6.0, Microsoft Visual C++®, Microsoft Visual J++™, or any language that can create COM components. This wide support for COM add-ins means that developers can now use multiple development environments to create custom solutions in Microsoft Office. The only requirement to connect a COM add-in to an Office application is for the add-in to implement the IDExtensibility2 interface. COM add-ins can be loaded when the host application starts, or on demand. Support has been added to allow the OnAction property of a custom command bar button to load a COM add-in. For a complete discussion of how to create, register, load, and work with COM add-ins, see Chapter 11, "Add-ins, Templates, Wizards, and Libraries."