1、首先在OCX的CPP文件中聲明一個全局變量：
static HHOOK hHook = NULL;
2、定義VHook處理函數：
LRESULT CALLBACK GetMessageProc(int nCode, WPARAM wParam, LPARAM lParam)
{
// Switch the module state for the correct handle to be used.
AFX_MANAGE_STATE(AfxGetStaticModuleState( ));
// If this is a keystrokes message, translate it in controls'
// PreTranslateMessage().
LPMSG lpMsg = (LPMSG) lParam;
if( (nCode >= 0) && (PM_REMOVE == wParam) &&
AfxGetApp()->PreTranslateMessage(lpMsg))
{
lpMsg->message = WM_NULL;
lpMsg->lParam = 0L;
lpMsg->wParam = 0;
}
// Passes the hook information to the next hook procedure in
// the current hook chain.
return ::CallNextHookEx(hHook, nCode, wParam, lParam);
}
3、在OCX的“OnCreate”中添加如下代碼：
// Because ActiveX control is an inproc server, it does not have a
// message pump. So, messages to child windows created by the
// ActiveX control are not going to be received by the control.
// Thus, we set up a message hook to call PreTranslateMessage().
// This results in the call to FilterToolTipMessage(), which
// activates tooltips.
hHook = ::SetWindowsHookEx(WH_GETMESSAGE, GetMessageProc,
AfxGetInstanceHandle(),GetCurrentThreadId());
4、釋放資源，在OCX的“OnDestroy”消息中添加如下代碼：
VERIFY(::UnhookWindowsHookEx(hHook));