C / C++ / MFC

ON_NOTIFY_EX(TTN_NEEDTEXT, 0, OnToolTipText)

BOOL CMyDialog::OnInitDialog()
{
    CDialog::OnInitDialog()

    EnableToolTips();
    return TRUE;
}

BOOL CMyDialog::OnToolTipText(UINT, NMHDR *pNMHDR, LRESULT *)
{   // get text for dialog's control's tooltips
    TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
    UINT nID = pNMHDR->idFrom;
    if (pTTT->uFlags & TTF_IDISHWND)
        // idFrom is actually the HWND of the tool
        nID = ::GetDlgCtrlID((HWND)nID);
    if(nID)
    {
        pTTT->lpszText = MAKEINTRESOURCE(nID);
        pTTT->hinst = AfxGetResourceHandle();
        return(TRUE);
    }
    return(FALSE);
}