Programming Windows®, Fifth Edition

Timer Basics

You can allocate a timer for your Windows program by calling the SetTimer function. SetTimer includes an unsigned integer argument specifying a time-out interval that can range (in theory) from 1 msec (millisecond) to 4,294,967,295 msec, which is nearly 50 days. The value indicates the rate at which Windows sends your program WM_TIMER messages. For instance, an interval of 1000 msec causes Windows to send your program a WM_TIMER message every second.

When your program is done using the timer, it calls the KillTimer function to stop the timer messages. You can program a “one-shot” timer by calling KillTimer during the processing of the WM_TIMER message. The KillTimer call purges the message queue of any pending WM_TIMER messages. Your ...