Programming Windows®, Fifth Edition

The Windows Programming Hurdles

Even with my explanation of HELLOWIN, the structure and workings of the program are probably still quite mysterious. In a short C program written for a character-mode environment, the entire program might be contained in the main function. In HELLOWIN, WinMain contains only program overhead necessary to register the window class, create the window, and retrieve and dispatch messages from the message queue.

All the real action of the program occurs in the window procedure. In HELLOWIN, this action is not much—WndProc simply plays a sound file and displays a text string in its window. But in later chapters, you’ll find that almost everything a Windows program does is in response to a message to a window procedure. ...