Visual C Component Object Model Tutorial

COM technology enables use of independent active pieces in a bigger program.

Component Object Modeling (COM) is Microsoft's technology that allows you to build independent active software components that interact and communicate with each other and a bigger application. A COM object does something that can be used and reused by applications that want to focus on the bigger picture.

Creating COM Objects

Microsoft Visual Studio, C++ compiler and libraries allow a programmer to create a basic COM object using a wizard. A COM object can interact with a database.

The COM Interface

A COM object has an interface, a set of functions, that is generic enough to be used by multiple calling programs or other COM objects. The application accesses features of a COM object via this interface. The COM technology provides a standard way of function calling across these interfaces.

Multi-platform Interoperability

A COM object is in its binary form and can be developed by a third party vendor. Therefore, usability and interactability of various such binary objects depends heavily on the COM technology as long as the underlying operating system and hardware remain unchanged.

References

• Microsoft: What is COM?

Resources

• "Inside OLE"; Kraig Brockschmidt; 1999