《windows核心编程》笔记（四）

定时器示例：

#include<tchar.h>

//Thecaptionofourmessagebox
TCHARg_szCaption[]=TEXT("TimedMessageBox");


//Howmanysecondswe'lldisplaythemessagebox
intg_nSecLeft=0;


//ThisisSTATICwindowcontrolIDforamessagebox
#defineID_MSGBOX_STATIC_TEXT0x0000ffff
//控件得值為即xFFFF

VOIDWINAPIMsgBoxTimeout(PVOIDpvContext,BOOLEANfTimeout)
{
//NOTE:Duetoathreadracecondition,itispossible(butveryunlikely)
//thatthemessageboxwillnotbecreatedwhenwegethere.
HWNDhwnd=FindWindow(NULL,g_szCaption);

if(hwnd!=NULL)
{
//Thewindowdoesexist;updatethetimeremaining.
TCHARsz[100];
wsprintf(sz,TEXT("Youhave%dsecondstorespond"),g_nSecLeft--);
SetDlgItemText(hwnd,ID_MSGBOX_STATIC_TEXT,sz);

if(g_nSecLeft==0)
{
//Thetimeisup;forcethemessageboxtoexit.
EndDialog(hwnd,IDOK);
}
}
else
{
//Thewindowdoesnotexistyet;donothingthistime.
//We'lltryagaininanothersecond.
}
}

intWINAPI_tWinMain(HINSTANCEhinstExe,HINSTANCE,PTSTRpszCmdLine,int)
{

chWindows9xNotAllowed();

//Howmanysecondswe'llgivetheusertorespond
g_nSecLeft=10;

//Createamultishot1secondtimerthatbeginsfiringafter1second.
HANDLEhTimerQTimer;
CreateTimerQueueTimer(&hTimerQTimer,NULL,MsgBoxTimeout,NULL,1000,1000,0);

//Displaythemessagebox
MessageBox(NULL,TEXT("Youhave10secondstorespond"),g_szCaption,MB_OK);

//Cancelthetimer&deletethetimerqueue
DeleteTimerQueueTimer(NULL,hTimerQTimer,NULL);

//Letusknowiftheuserrespondedorifwetimed-out.
MessageBox(NULL,(g_nSecLeft==0)?TEXT("Timeout"):TEXT("Userresponded"),TEXT("Result"),MB_OK);

return(0);
}

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />