Lesson 1

To be an effective COM programmer, you must spend some time studying COM fundamentals. This module and the next module discuss core COM concepts. These will provide a foundation for understanding how the active template library (ATL) supports COM development. Your time spent understanding core COM concepts will make your COM programming efforts more efficient.
In this module, we will explore COM's binary standard via method and interface requirements. We will examine the IUnknown interface, describing interfaces with

1. interface definition language (IDL),
2. COM objects,
3. interface navigation, and
4. reference counting.

Finally, we will use IDL to describe a COM object and its interfaces and to produce a type library.
At the end of the module you will be able to:

1. Develop IUnknown methods for interface navigation and reference counting
2. Develop your own custom COM interfaces
3. Use IDL to describe COM interfaces and COM objects
4. Use IDL to produce a type library

To get the most out of this module, you should be familiar with the following C++ concepts:

1. classes and structures,
2. constructors,
3. inheritance,
4. multiple inheritance,
5. virtual functions, and
6. pure virtual functions.

You do not have to be an expert in these areas.If you need a refresher, check out one of the books recommended on the Resources page.