afx_msg BOOLOnToolTip(UINTid,NMHDR *pNMHDR,LRESULT*pResult);
ON_NOTIFY_EX(TTN_NEEDTEXT,0,OnToolTip)  

BOOL CMainDlg::OnToolTip(UINTid,NMHDR *pNMHDR,LRESULT*pResult) 
{
     TOOLTIPTEXT   *pTTT=(TOOLTIPTEXT*)pNMHDR;  
     UINT  uID=pNMHDR->idFrom;  
     if(pTTT->uFlags  & TTF_IDISHWND)  
     {   
         uID=::GetDlgCtrlID((HWND)uID);  
     }
     if(uID==NULL) 
     {
         return   FALSE;  
     }
     switch(uID)
     {  
         case ID_BTN_SELECT_TOOLBOX:
              pTTT->lpszText =_T("选择");  
              break;
         default:
              break;
     }
     return   TRUE;
}