changing tool tip for a toolbar button

I took a look into the MFC source codes, and surprisingly the tool-tips are NOT handled by
CToolBar but by the CFrameWnd(CMainFrame) which contains the CToolBar. The problem is,
in the source code the tool tip texts are read directly from the tool-bar resource - no chance to
edit or alter them(Take a look at the source code below).
The only way is to modify the routine itself which is much easier than it sounds.

1. Iin your BEGIN_MESSAGE_MAP/END_MESSAGE_MAP of your CMainFrame you
    have to add:
    ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTW, 0, 0xFFFF, OnToolTipText)
    ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTA,  0, 0xFFFF, OnToolTipText)
    These two lines map the tool-tip text request which is sent by the tool bar to your
    CMainFrame.

2. Now take a look into the original handler
    (defined in 'WINFRM.CPP' in your MFC source dir which is on my machine
     \MSDEV\MFC\SRC)


BOOL CFrameWnd::OnToolTipText(UINT, NMHDR* pNMHDR, LRESULT* pResult)
{
ASSERT(pNMHDR->code == TTN_NEEDTEXTA || pNMHDR->code == TTN_NEEDTEXTW);

// allow top level routing frame to handle the message
if (GetRoutingFrame() != NULL)
return FALSE;

// need to handle both ANSI and UNICODE versions of the message
TOOLTIPTEXTA* pTTTA = (TOOLTIPTEXTA*)pNMHDR;
TOOLTIPTEXTW* pTTTW = (TOOLTIPTEXTW*)pNMHDR;
TCHAR szFullText[256];
CString strTipText;
UINT nID = pNMHDR->idFrom;
if (pNMHDR->code == TTN_NEEDTEXTA && (pTTTA->uFlags & TTF_IDISHWND) ||
pNMHDR->code == TTN_NEEDTEXTW && (pTTTW->uFlags & TTF_IDISHWND))
{
// idFrom is actually the HWND of the tool
nID = _AfxGetDlgCtrlID((HWND)nID);
}

/********************/
/**** !!!!!!!!!!! THIS IS THE IMPORTANT PART <---------------------- ******/
/********************/
if (nID != 0) // will be zero on a separator
{
AfxLoadString(nID, szFullText);
      // this is the command id, not the button index
AfxExtractSubString(strTipText, szFullText, 1, '\n');
}
#ifndef _UNICODE
if (pNMHDR->code == TTN_NEEDTEXTA)
lstrcpyn(pTTTA->szText, strTipText, _countof(pTTTA->szText));
else
_mbstowcsz(pTTTW->szText, strTipText, _countof(pTTTW->szText));
#else
if (pNMHDR->code == TTN_NEEDTEXTA)
_wcstombsz(pTTTA->szText, strTipText, _countof(pTTTA->szText));
else
lstrcpyn(pTTTW->szText, strTipText, _countof(pTTTW->szText));
#endif
*pResult = 0;

return TRUE;    // message was handled
}


3. Now take a look at the part after the line with "THIS IS THE IMPORTANT PART"

>>AfxLoadString(nID, szFullText);
>>      // this is the command id, not the button index
>>AfxExtractSubString(strTipText, szFullText, 1, '\n');

Here you have got the message ID(for ex ID_FILE_OPEN) in the var nID. After these lines,
strTipText contains the string which will be displayed as the tool tip.

* Now you could implement something like switch(nID) { ... }

* Or you add a "CArray<CString,CString&>  myToolTips" to your CFrameWnd, and use
  something like that:

 // 0<=buttonIndex<count of buttons
  int buttonIndex=m_wndToolBar.CommandToIndex(nID);
  strToolTip=myToolTips[buttonIndex]

So you can change tool tips by changing myToolTips.

Perhaps you like to set them up to the initial values:

CMainFrame::OnCreate()
{
.. <class wiz created stuff here>

// insert this before return 0;

int i,nButtons=m_wndToolBar.GetToolBarCtrl().GetButtonCount();
for(i=0;i<nButtons;i++) {
  CString szFullText,szToolTip;
  UINT nID; // command ID

  nID=m_wndToolBar.GetItemID();
  AfxLoadString(nID, szFullText);
  AfxExtractSubString(szToolTip, szFullText, 1, '\n');

  myToolTips.SetAtGrow(i,szToolTip);
}

I hope this will help you.
If you want i can send you some sample code, just mail me at alexander.berthold@rol3.com

I solved my problem, I just needed to toggle between 2 different messages, so I defined them both in the string table, and then just changed the object ID of the toolbar button in question whenever I needed, since that is easy.

thanks so much for all your help.
Anthony