winapi - Prevent windows from going into sleep when my program is running? -

i have stop windows going sleep when program running.

and don't want prevent sleep-timer, want cancel sleep-event if press sleep-button or in other way actively tell computer sleep. therefore setthreadexecutionstate not enough.

or...i don't have prevent sleep completely, delay 5-10sec allow program finish task.

(i know bad program behavior it's personal use.)

i had problem hardware device connected via usb. xp /vista sleep/hibernate right in middle of ... great say, when resumes can continue. if hardware still connected!!! users have habit of pulling cables out whenever feel it.

you need handle xp , vista

under xp trap wm_powerbroadcast , pbt_apmquerysuspend wparam.

   // see if bit 1 set, means can send deny while busy    if (message.lparam & 0x1)    {       // send deny message       return broadcast_query_deny;    } // if    else    {       return true;    } // else 

under vista use setthreadexecutionstate this

// try vista, fail on xp if (setthreadexecutionstate(es_continuous | es_system_required | es_awaymode_required) == null) {    // try xp variant make sure     setthreadexecutionstate(es_continuous | es_system_required); }  // if  

and when app has finished set normal

// set state normal setthreadexecutionstate(es_continuous);