问MFC中复选框控件中禁用复选框的工具提示

EN

class CMyCheckListBox : public CCheckListBox
{
    DECLARE_DYNAMIC(CMyCheckListBox)

public:
  CMyCheckListBox(){};
  virtual ~CMyCheckListBox(){};
  afx_msg int OnToolHitTest(CPoint point, TOOLINFO * pTI) const;
  UINT ItemFromPoint2(CPoint pt, BOOL& bOutside) const;
  BOOL OnToolTipText( UINT id, NMHDR * pNMHDR, LRESULT * pResult );

protected:
  virtual void PreSubclassWindow();
  DECLARE_MESSAGE_MAP()
};   

        This will work only for Unicode strings.

IMPLEMENT_DYNAMIC(CMyCheckListBox, CCheckListBox)

BEGIN_MESSAGE_MAP(CMyCheckListBox, CCheckListBox)
  ON_NOTIFY_EX_RANGE(TTN_NEEDTEXT, 0, 0xFFFF, OnToolTipText)
END_MESSAGE_MAP()

void CMyCheckListBox::PreSubclassWindow() {
    CCheckListBox::PreSubclassWindow();
    EnableToolTips(TRUE);
}
int CMyCheckListBox::OnToolHitTest(CPoint point, TOOLINFO * pTI) const{
    int row;
    RECT cellrect;  
    BOOL tmp = FALSE;
    row  = ItemFromPoint(point,tmp);  
    if ( row == -1 ) 
        return -1;
    GetItemRect(row,&cellrect);
    pTI->rect = cellrect;
    pTI->hwnd = m_hWnd;
    pTI->uId = (UINT)((row));  
    pTI->lpszText = LPSTR_TEXTCALLBACK;
    return pTI->uId;
}
BOOL CMyCheckListBox::OnToolTipText( UINT id, NMHDR * pNMHDR, LRESULT * pResult ){
    TOOLTIPTEXTW* pTTTW = (TOOLTIPTEXTW*)pNMHDR;
    CString strTipText;
    UINT nID = pNMHDR->idFrom;

    GetText( nID ,strTipText);
    lstrcpyn(pTTTW->szText, strTipText, 80);

    *pResult = 0;
  return TRUE;    
}
UINT CMyCheckListBox::ItemFromPoint2(CPoint pt, BOOL& bOutside) const{
    int nFirstIndex, nLastIndex;
    nFirstIndex = GetTopIndex();
    nLastIndex = nFirstIndex  + GetCount(); 
    bOutside = TRUE;
    CRect Rect;
    int nResult = -1;
    for (int i = nFirstIndex; nResult == -1 && i <= nLastIndex; i++){
        if (GetItemRect(i, &Rect) != LB_ERR){
            if (Rect.PtInRect(pt)){
                nResult  = i;
                bOutside = FALSE;
            }
        }   
    }
    return nResult;
}