有关钩子函数的小问题

LRESULT CALLBACK JournalLogProc(int nCode,WPARAM wparam,LPARAM lparam)//钩子函数

{

	if(nCode<0)

		return CallNextHookEx(hook,nCode,wparam,lparam);

	if(HC_ACTION==nCode)

	{

		EVENTMSG* pEvt=(EVENTMSG*)lparam;

		if(pEvt->message==WM_KEYDOWN)

		{

			int vKey=LOBYTE(pEvt->paramL);   //取得虚拟键值

			if((GetKeyState(VK_MENU)<0)&&((int)('Q')==vKey))

				start();

			if((GetKeyState(VK_MENU)<0)&&((int)('S')==vKey))

			{

				HWND hwnd=NULL;

				hwnd=FindWindow(NULL,"mytool");

				if(tag==-1)

				{

					tag*=(-1);

					ShowWindow(hwnd,SW_HIDE);

				}

				else

				{

					tag*=(-1);

					ShowWindow(hwnd,SW_SHOW);

				}

			}

		}

	}

	return CallNextHookEx(hook,nCode,wparam,lparam);

}



void SetHook()//设置钩子

{

	hook=SetWindowsHookEx(WH_JOURNALRECORD,JournalLogProc,GetModuleHandle("tool.dll"),0);

}



void StopHook()

{

	if(hook!=NULL)

	{

		UnhookWindowsHookEx(hook);

		hook=NULL;

	}

}