timeSetEvent
The timeSetEvent function starts a specified timer event. The multimedia timer runs in its own thread. After the event is activated, it calls the specified callback function or sets or pulses the specified event object.
This function is obsolete. New applications should use CreateTimerQueueTimer to create a timer-queue timer.
MMRESULT timeSetEvent(
UINT uDelay,
UINT uResolution,
LPTIMECALLBACK lpTimeProc,
DWORD_PTR dwUser,
UINT fuEvent
);
Parameters
uDelay
Event delay, in milliseconds. If this value is not in the range of the minimum and maximum event delays supported by the timer, the function returns an error.
uResolution
Resolution of the timer event, in milliseconds. The resolution increases with smaller values; a resolution of 0 indicates periodic events should occur with the greatest possible accuracy. To reduce system overhead, however, you should use the maximum value appropriate for your application.
lpTimeProc
Pointer to a callback function that is called once upon expiration of a single event or periodically upon expiration of periodic events. If fuEvent specifies the TIME_CALLBACK_EVENT_SET or TIME_CALLBACK_EVENT_PULSE flag, then the lpTimeProc parameter is interpreted as a handle to an event object. The event will be set or pulsed upon completion of a single event or periodically upon completion of periodic events. For any other value of fuEvent, the lpTimeProc parameter is interpreted as a function pointer with the following signature: void (CALLBACK)(UINT uTimerID, UINT uMsg, DWORD_PTR dwUser, DWORD_PTR dw1, DWORD_PTR dw2);
dwUser
User-supplied callback data.
fuEvent
Timer event type. This parameter may include one of the following values.
Value | Meaning |
TIME_ONESHOT | Event occurs once, after uDelay milliseconds. |
TIME_PERIODIC | Event occurs every uDelay milliseconds. |
The fuEvent parameter may also include one of the following values.
Value | Meaning |
TIME_CALLBACK_FUNCTION | When the timer expires, Windows calls the function pointed to by the lpTimeProc parameter. This is the default. |
TIME_CALLBACK_EVENT_SET | When the timer expires, Windows calls the SetEvent function to set the event pointed to by the lpTimeProc parameter. The dwUser parameter is ignored. |
TIME_CALLBACK_EVENT_PULSE | When the timer expires, Windows calls the PulseEvent function to pulse the event pointed to by the lpTimeProc parameter. The dwUser parameter is ignored. |
TIME_KILL_SYNCHRONOUS | Passing this flag prevents an event from occurring after the timeKillEvent() function is called. |
Return Values
Returns an identifier for the timer event if successful or an error otherwise. This function returns NULL if it fails and the timer event was not created. (This identifier is also passed to the callback function.)
Remarks
Each call to timeSetEvent for periodic timer events requires a corresponding call to the timeKillEvent function.
Creating an event with the TIME_KILL_SYNCHRONOUS and the TIME_CALLBACK_FUNCTION flag prevents the event from occurring after the timeKillEvent function is called.
Requirements
** Windows XP:** Included in Windows XP only.
** Header:** Declared in Mmsystem.h; include Windows.h.
** Library:** Use Winmm.lib.
See Also
Multimedia Timers, Multimedia Timer Functions, PulseEvent, SetEvent, timeKillEvent