Timers (SetTimer and CreateWaitableTimer) in Windows |
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SetTimerThe following example creates a timer (that is not attached to a window) whose Timer Procedure creates 20 Message Boxes
#include <windows.h>
class foo_class {
static int counter;
public:
static void __stdcall timer_proc(HWND,unsigned int, unsigned int, unsigned long) {
if (counter++ < 20)
MessageBox(0,"Hello","MessageBox",0);
else
PostQuitMessage(0);
}
};
int foo_class::counter=0;
WINAPI WinMain(HINSTANCE,HINSTANCE,LPSTR,int) {
int iTimerID = SetTimer(0, 0, 300, foo_class::timer_proc);
MSG m;
while (GetMessage(&m,0,0,0)) {
TranslateMessage(&m);
DispatchMessage(&m);
}
return 1;
}
CreateWaitableTimerThis example demonstrates how to use Timers in windows. A timer will be set that is signalled for the first time 2 seconds after the first call to CreateWaitableTimer and then is signalled every 3/4th of a second.
#define _WIN32_WINNT 0x0400
#include <windows.h>
#include <process.h>
#include <stdio.h>
unsigned __stdcall TF(void* arg) {
HANDLE timer=(HANDLE) arg;
while (1) {
WaitForSingleObject(timer,INFINITE);
printf(".");
}
}
int main(int argc, char* argv[]) {
HANDLE timer = CreateWaitableTimer(
0,
false, // false=>will be automatically reset
0); // name
LARGE_INTEGER li;
const int unitsPerSecond=10*1000*1000; // 100 nano seconds
// Set the event the first time 2 seconds
// after calling SetWaitableTimer
li.QuadPart=-(2*unitsPerSecond);
SetWaitableTimer(
timer,
&li,
750, // Set the event every 750 milli Seconds
0,
0,
false);
_beginthreadex(0,0,TF,(void*) timer,0,0);
// Wait forever,
while (1) ;
return 0;
}
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http://www.adp-gmbh.ch/win/misc/timer.html