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MFC
SetTimer: WM_TIMER
with VC++
Sample
Source Code
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Windows timers are mechanisms that let you set one or more
timers to be triggered at a specific number of milliseconds. If you set a timer to be triggered at a 1,000 millisecond interval, it triggers every second. When a timer triggers, it sends a WM_TIMER
message to your application. You can use the Class Wizard to add a function to your application to handle this timer message.
Timer events are placed only in the application event queue if that queue is empty and the application is idle. Windows does not place timer event messages in the application event queue if the application is already busy. If your application has been busy and has missed several timer event messages, Windows places only a single timer message in the event queue. Windows does not send your application all the timer event messages that occurred while your application was busy. It doesn't matter how many timer messages your application may have missed; Windows still places only a single timer message in your queue.
When you start or stop a timer, you specify a timer ID, which can be any integer value. Your application uses this timer ID to determine which timer event has triggered, as well as to start and stop timers.
After
you add all the variables using the Class Wizard,
Adding
the Timer IDs:
#ifdef
_DEBUG
#define
new DEBUG_NEW
#undef
THIS_FILE
static
char THIS_FILE[] = __FILE__;
#endif
Add
the following Code after this code in the
TimerEventView.cpp:
#define
IDT_TIMER WM_USER
+ 200
int
iHour,iMinute,iSecond;
CString
Label;
BOOL
Status=FALSE;
Add
the following Variables in the TimerEventView.h in the
public section
UINT
Timeval;
Add
the following function definitions in the TimerEventView.h
.After this comment write the following code.
Protected:
//
Generated message map functions
afx_msg
UINT StartTimer
(UINT TimerDuration);
// Start the Timer
afx_msg
BOOL StopTimer (UINT TimerVal);
// Stop the Timer
afx_msg
BOOL MyTucancode.net(CString strType);
// Perform the Operation
afx_msg
void OnCheck();
// Perform the Validation
afx_msg
void OnUnlock();
// Unlock the System
Starting
the Clock Timer:
To
start the clock timer, you need to edit the OnInitUpdate
function Add the new code:
void
CShutEvtView::OnInitialUpdate()
{
CFormView::OnInitialUpdate();
GetParentFrame()->RecalcLayout();
ResizeParentToFit();
/*
My Code Starts Here*/
m_cUTime.SetFocus();
m_cCancel.EnableWindow(FALSE);
Timeval=StartTimer(1000);
SetWindowPos(&CWnd::wndTop,
670, 350, 0, 0, SWP_SHOWWINDOW|SWP_NOSIZE);
}
THE
StartTimer
FUNCTION:
UINT
CTimerEventView::StartTimer (UINT TimerDuration)
{
UINT TimerVal;
TimerVal = SetTimer
(IDT_TIMER, TimerDuration, NULL); // Starting the
Timer
if (TimerVal == 0)
{
AfxMessageBox("Unable to obtain timer");
}
return TimerVal;
}// end StartTimer
THE
StopTimer
FUNCTION:
BOOL
CTimerEventView::StopTimer (UINT TimerVal)
{
if (!KillTimer
(TimerVal))
{
return FALSE;
}
// Place clean-up code following this
point.
return TRUE;
} // end StopTimer
THE
OnCancel
FUNCTION:
void
CTimerEventView::OnCancel()
{
m_cUTime.EnableWindow(TRUE);
//Enabling the Shutdown Time Edit Control
m_cExit.EnableWindow(TRUE);
//Enable Exit Button
m_cOperation.EnableWindow(TRUE);
//Enable List Control
Status=TRUE;
}
THE
OnExit
FUNCTION:
void
CTimerEventView::OnExit()
{
if(StopTimer(Timeval)==FALSE)
::MessageBox(NULL,"Error
While Killing the Timer","ShutEvt",1);
::PostQuitMessage(1);
}
THE
OnUnlock
FUNCTION:
void
CTimerEventView::OnUnlock()
{
WinExec("rundll32
user32.dll,LockWorkStation",1); // Lock
the System
}
THE
OnCheck FUNCTION: This functions is to validate the date
entered by user
void
CTimerEventView::OnCheck()
{
int iLHour,iLMinute;
CString tmpTime,subTime;
UpdateData();
tmpTime=m_sUserTime;
iLHour=tmpTime.Find(":",0);
subTime=tmpTime.Left(iLHour);
iHour=atoi(subTime);
if(iLHour==2 && iHour>=0 && iHour<=24)
{
iLMinute=tmpTime.Find(":",iLHour);
subTime=tmpTime.Mid(iLHour+1);
subTime=subTime.Left(iLMinute);
iMinute=atoi(subTime);
if(iLMinute==2 && iMinute>=0 && iMinute<=60)
{
iSecond=atoi(tmpTime.Right(2));
if(iSecond>=0 && iSecond<=60)
{
m_cUTime.EnableWindow(FALSE);
m_cCancel.EnableWindow(TRUE);
m_cExit.EnableWindow(FALSE);
m_cOperation.EnableWindow(FALSE);
}
else
::MessageBox(NULL,"Enter the Date in HH:MM:SS
\n\n OR \n\n Seconds Should be between 0 and
60","ShutEvt",1);
}
else
::MessageBox(NULL,"Enter the Date in HH:MM:SS\n\n OR
\n\n Minutes Should be between 0 and
60","ShutEvt",1);
}
else
::MessageBox(NULL,"Enter the Date in HH:MM:SS \n\n OR
\n\n Hour should be between 0 and
24","ShutEvt",1);
}
THE
MyTucancode.net
FUNCTION:
This
function is to perform the tucancode.net selected by user from the
CComboBox
BOOL
CTimerEventView::MyTucancode.net(CString strType)
{
HANDLE hToken;
TOKEN_PRIVILEGES tkp;
// Stop the timer before shutdown
StopTimer(Timeval);
// Get a token for this process.
if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken))
return( FALSE );
// Get the LUID for the shutdown privilege.
LookupPrivilegeValue(NULL, SE_SHUTDOWN_NAME,
&tkp.Privileges[0].Luid);
tkp.PrivilegeCount = 1; // one privilege to set
tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
// Get the shutdown privilege for this process.
AdjustTokenPrivileges(hToken, FALSE, &tkp, 0,
(PTOKEN_PRIVILEGES)NULL, 0);
if (GetLastError() != ERROR_SUCCESS)
return FALSE;
// Shut down the system and force all applications to
close.
// if (!ExitWindowsEx(EWX_POWEROFF | EWX_POWEROFF |
EWX_FORCE, 0))
if(strType=="LogOff")
{
if(!ExitWindowsEx(EWX_LOGOFF | EWX_FORCE, 0))
return FALSE;
}
else if(strType=="ShutDown")
{
if(!ExitWindowsEx(EWX_SHUTDOWN|EWX_POWEROFF| EWX_FORCE,
0))
return FALSE;
}
else if(strType=="Restart")
{
if(!ExitWindowsEx(EWX_REBOOT| EWX_FORCE, 0))
return FALSE;
}
return TRUE;
}
THE
OnSelchangeOperation
FUNCTION:
Add this function through ClassWizard for the Comboxbox
Control.(CBN_SELCHANGE)
void
CTimerEventView::OnSelchangeOperation()
{
Status=FALSE;
int Selection=m_cOperation.GetCurSel();
OnCheck();
m_cOperation.GetLBText(Selection,Label);
}
Handling
the Clock Timer Event
Now that you've started a
timer, you need to add the code to handle the timer event
message. You can do this by following these steps:
1.
Using the Class Wizard,
add a variable to the IDC_STATIC control of type CString
named m_sCurrtime.
2.
Using the Class Wizard,
add a function to handle the WM_TIMER message for the
CTimerEvent object.
3.
Edit the OnTimer function,
adding the following code:
THE
OnTimer FUNCTION.
void
CTimerEventView::OnTimer(UINT
nIDEvent)
{
CTime ct=CTime::GetCurrentTime();
char *str=new char[10];
UpdateData();
m_sCurrtime.Format("%d : %d : %d ",ct.GetHour(),ct.GetMinute(),ct.GetSecond());
UpdateData(FALSE);
if(iHour==ct.GetHour() && iMinute==ct.GetMinute()
&& iSecond==ct.GetSecond() &&
Label=="Lock" && Status==FALSE)
{
OnUnlock();
m_cUTime.EnableWindow(TRUE);
//Enabling the Shutdown Time Edit Control
m_cExit.EnableWindow(TRUE);
//Enable Exit Button
m_cOperation.EnableWindow(TRUE);
//Enable List Control
//StopTimer(Timeval);
Status=TRUE;
}
if(iHour==ct.GetHour() && iMinute==ct.GetMinute()
&& iSecond==ct.GetSecond() &&
Label=="LogOff" && Status==FALSE)
{
MyTucancode.net ("LogOff");
}
if(iHour==ct.GetHour() && iMinute==ct.GetMinute()
&& iSecond==ct.GetSecond() &&
Label=="ShutDown" && Status==FALSE)
{
MyTucancode.net ("ShutDown");
}
if(iHour==ct.GetHour() && iMinute==ct.GetMinute()
&& iSecond==ct.GetSecond() &&
Label=="Restart" && Status==FALSE)
{
MyTucancode.net ("Restart");
}
delete [] str;
CFormView::OnTimer(nIDEvent);
}
Download
the Sample
Project here.
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