CWnd::SetTimer UINT SetTimer( UINT nIDEvent, UINT nElapse, void (CALLBACK EXPORT* lpfnTimer)(HWND, UINT, UINT, DWORD) );Return ValueThe timer identifier of the new timer if the function is successful. An application passes this value to the KillTimer member function to kill the timer. Nonzero if successful; otherwise 0.ParametersnIDEventSpecifies a nonzero timer identifier.nElapseSpecifies the time-out value, in milliseconds.lpfnTimerSpecifies the address of the application-supplied TimerProc callback function that processes the WM_TIMER messages. If this parameter is NULL, the WM_TIMER messages are placed in the application’s message queue and handled by the CWnd object.ResInstalls a system timer. A time-out value is specified, and every time a time-out occurs, the system posts aWM_TIMER message to the installing application’s message queue or passes the message to an application-defined TimerProc callback function. The lpfnTimer callback function need not be named TimerProc, but it must be defined as follows:void CALLBACK EXPORT TimerProc( HWND hWnd, // handle of CWnd that called SetTimer UINT nMsg, // WM_TIMER UINT nIDEvent // timer identification DWORD dwTime // system time );Timers are a limited global resource; therefore it is important that an application check the value returned by the SetTimer member function to verify that a timer is actually available.Example// This example shows how to use CWnd::SetTimer, CWnd::KillTimer, and how to handle WM_TIMER messages. A timer is set up to send a WM_TIMER message to the main frame window every 2 seconds in OnStartTimer(). OnStopTimer will stop the timer by calling CWnd::KillTimer. OnTimer was set up through class wizard to handle WM_TIMER messages for the main frame window. In this example the PC speaker will beep every 2 seconds.void CMainFrame::OnStartTimer() { m_nTimer = SetTimer(1, 2000, 0); }void CMainFrame::OnStopTimer() { KillTimer(m_nTimer); }void CMainFrame::OnTimer(UINT nIDEvent) { MessageBeep(0xFFFFFFFF); // Beep // Call base class handler. CMDIFrameWnd::OnTimer(nIDEvent); }
UINT SetTimer( UINT nIDEvent, UINT nElapse, void (CALLBACK EXPORT* lpfnTimer)(HWND, UINT, UINT, DWORD) );Return ValueThe timer identifier of the new timer if the function is successful. An application passes this value to the KillTimer member function to kill the timer. Nonzero if successful; otherwise 0.ParametersnIDEventSpecifies a nonzero timer identifier.nElapseSpecifies the time-out value, in milliseconds.lpfnTimerSpecifies the address of the application-supplied TimerProc callback function that processes the WM_TIMER messages. If this parameter is NULL, the WM_TIMER messages are placed in the application’s message queue and handled by the CWnd object.ResInstalls a system timer. A time-out value is specified, and every time a time-out occurs, the system posts aWM_TIMER message to the installing application’s message queue or passes the message to an application-defined TimerProc callback function. The lpfnTimer callback function need not be named TimerProc, but it must be defined as follows:void CALLBACK EXPORT TimerProc(
HWND hWnd, // handle of CWnd that called SetTimer
UINT nMsg, // WM_TIMER
UINT nIDEvent // timer identification
DWORD dwTime // system time
);Timers are a limited global resource; therefore it is important that an application check the value returned by the SetTimer member function to verify that a timer is actually available.Example// This example shows how to use CWnd::SetTimer, CWnd::KillTimer, and how to handle WM_TIMER messages. A timer is set up to send a WM_TIMER message to the main frame window every 2 seconds in OnStartTimer(). OnStopTimer will stop the timer by calling CWnd::KillTimer. OnTimer was set up through class wizard to handle WM_TIMER messages for the main frame window. In this example the PC speaker will beep every 2 seconds.void CMainFrame::OnStartTimer()
{
m_nTimer = SetTimer(1, 2000, 0);
}void CMainFrame::OnStopTimer()
{
KillTimer(m_nTimer);
}void CMainFrame::OnTimer(UINT nIDEvent)
{
MessageBeep(0xFFFFFFFF); // Beep // Call base class handler.
CMDIFrameWnd::OnTimer(nIDEvent);
}
最后一个参数为NULL表示在OnTimer中处理
killTimer(m_timer);