Sams Teach Yourself Microsoft® Windows® DNA Programming in 21 Days

Component Object Model (COM)

Microsoft's Component Object Model (COM) was covered briefly on Day 1, "Understanding Windows DNA." Today, we will examine COM in a little more detail to better understand its importance in Windows DNA. Let's begin by examining the history of COM.

A Brief History of COM

There are primarily two technologies that were the direct precursors to COM: Dynamic Data Exchange (DDE) and Object Linking and Embedding (OLE).

In November 1987, Microsoft introduced DDE in Windows 2.03. Although the ability to cut and paste was already incorporated into Windows, it was difficult to modify the pasted elements when the source data changed. DDE established a protocol for exchanging information between Windows-based applications and ...