Odd bug in CMFCToolbarComboBoxButton class

[Santanu Lahiri]

Hello, I am trying to use this control in a toolbar. For the most part the code works. However, I am running into this odd problem that I am getting partial text back when I call GetText. The app requires that when I click a different button in the toolbar, I check the combo box and retrieve the text from it for processing. That is when this bug surfaces. The last character is getting truncated. If I retrieve the text in response to the Enter key handler for the combo box, I get the full text using the same GetText call. Here is the code...most all of it is lifted from the samples. CObList listButtons; if (CMFCToolBar::GetCommandButtons(ID_EDT_FIND_NDC, listButtons) > 0) {     for (POSITION posCombo = listButtons.GetHeadPosition();     pSrcCombo == NULL && posCombo != NULL; )     {        CMFCToolBarComboBoxButton* pCombo = DYNAMIC_DOWNCAST(CMFCToolBarComboBoxButton, listButtons.GetNext(posCombo));        if (pCombo != NULL) pSrcCombo = pCombo;     } } if (pSrcCombo != NULL) { ASSERT_VALID(pSrcCombo); LPCTSTR lpszSelItem = pSrcCombo->GetText(); ... } So if the combo box has the text '1234567890', I am getting back '123456789' in one case, and '1234567890' in another case, depending on whether I press the other button or press the Enter key. Has anyone encountered this, and can someone suggest a solution? Thanks for your time.

[PatrikE]

I just encountered the same problem here! No solution so far. It is so frustrating to work with this feature pack...

[PatrikE]

At least this works for me: In the Code, where a character is truncated replace the call to pSrcCombo->GetText() with something like this: CComboBox* a_pComboBox(pSrcCombo->GetComboBox()); ASSERT(a_pComboBox); CString a_strAddressTextInCombo; a_pComboBox->GetWindowText(a_strAddressTextInCombo); Maybe in your code you have to distinguish somehow where the call comes from... Or you could try if the above code works for both scenarios. Hope I could help, Patrik

[Santanu Lahiri]

Yes, I finally got frustrated enough to think up alternatives. I had already coded to find the CMFCToolbarComboBoxButton object (Code from MSDN actually), so now I went ahead and code along the following lines:

if (pSrcCombo != NULL)
{
    ASSERT\_VALID(pSrcCombo);
    CMFCToolBarComboBoxEdit \*pEdit = (CMFCToolBarComboBoxEdit \*) pSrcCombo->GetEditCtrl();
    if (pEdit)
    {
        CString strSelItem=\_T("");
        pEdit->GetWindowText (strSelItem);
        pSrcCombo->AddItem (strSelItem);
        ...
    }
}

Using the Edit Control seems to have solved the problem for me. At the MFCToolbarComboBoxButton level, there is no option for a fix that I have found. Perhaps subclassing the control and intercepting the GetText() call may work, but I have not tried it.

modified on Tuesday, October 20, 2009 4:07 PM

[Santanu Lahiri]

Yes, a code sample in the MSDN website gives details on how to identify the control that you are using.

CMFCToolBarComboBoxButton\* pSrcCombo = NULL;

CObList listButtons;
if (CMFCToolBar::GetCommandButtons(ID\_EDT\_FIND\_NDC, listButtons) > 0)
{
	for (POSITION posCombo = listButtons.GetHeadPosition();
		pSrcCombo == NULL && posCombo != NULL;)
	{
		CMFCToolBarComboBoxButton\* pCombo = DYNAMIC\_DOWNCAST(CMFCToolBarComboBoxButton, listButtons.GetNext(posCombo));

		if (pCombo != NULL && CMFCToolBar::IsLastCommandFromButton(pCombo))
		{
			pSrcCombo = pCombo;
		}
	}
}