Message-Based Programming

Abstract

The first step in writing a graphics application for Windows 98 is to understand the message-based programming style which the operating system demands. A Windows 98 program must operate by processing the messages that it is sent — these messages originate with user input and are subsequently translated by the operating system before being passed to the program. The message-based approach contrasts strongly with the more traditional technique of allowing the program to dictate step-by-step the range of acceptable inputs — the Windows 98 operating system gives the user much more control. This chapter describes the following essential concepts:

• generation of messages from user input

• message queues and the program’s message loop

• handling messages with callback functions

• Windows 98 messages