Re: Why this strange behaviour regarding subclassing controls

From:
David Wilkinson <no-reply@effisols.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Thu, 25 May 2006 13:40:52 -0400
Message-ID:
<eweHYJCgGHA.4004@TK2MSFTNGP04.phx.gbl>
bhargavi_ks2001@yahoo.com wrote:

hi
I am unable to solve this after spending lot of time ,Can someon ehelp
me out here
I get assertion here and the window becomes NULLL after assigning in
the OnIntialUpdate of formView.--afxwin2.inl
// CWnd
_AFXWIN_INLINE CWnd::operator HWND() const
    { return this == NULL ? NULL : m_hWnd; }

The problem is subclassing controls and the communication between each
subclassed control
In a view
there ia
One List Control -
One TabControl and inside the tabcontrol there are 2 list controls
These 2 list controls are in a Dialog1 - CTab1

The communication happens fine between the list control and the list
control which is inside the tab control.

The communication fails between the 2 list controls inside the tab
control.
Am i missing any basics here?
Pls guide
Here is the code for data exchnage and when I click the first list
control it comes in DDX exchange but not the when I clcik inside the
tab control.
I get assertion error

***********CCView.cpp
void CCView::DoDataExchange(CDataExchange* pDX)
{
    CFormView::DoDataExchange(pDX);
    DDX_Control(pDX, IDC_LIST_RESULTS2, m_myListSeriesCtrl);
    DDX_Control(pDX, IDC_AUTO_DELETE, m_CtrlAutoDelete);
    DDX_Control(pDX, IDC_TAB_CTRL, m_myCtrlTab);

}

----CTab1.cpp
void CTab1::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    DDX_Control(pDX, IDC_LIST_SERIES1, m_myListSeriesCtrlinTab);
    DDX_Control(pDX, IDC_IMAGE_LSTCTRL, m_IconsListCtrl);

}

I call these function from teh OnInitialUpdate of CCView derieved from
CFormView

m_myListSeriesCtrl.SetTabToFill(tab1); //First List control of tab
control
m_ResultsCtrl.SetTabToFill(tab1); //Second List control of tab control

In the onClick of FirstList Control
void CMyListSeriesCtrl::OnNMClick(NMHDR *pNMHDR, LRESULT *pResult)
{
    // TODO: Add your control notification handler code here
    //m_pmyListSeriesCtrl->DeleteAllItems();
    my_tab1->m_myListSeriesCtrlinTab.DeleteAllItems();
    CString strMessage;
    *pResult = 0;
    int nRow = GetNextItem(-1, LVNI_SELECTED);
    strMessage.Format(_T("Row selected is % d "),nRow +1);
    //AfxMessageBox(strMessage);
    CString ItemData1= GetItemText(nRow,0);
    //AfxMessageBox(ItemData1);
    CString ItemData2= GetItemText(nRow,1);
    //AfxMessageBox(ItemData2);
    CString ItemData3= GetItemText(nRow,2);

    //AfxMessageBox(ItemData1 + ItemData2 + ItemData3);

    my_tab1->m_myListSeriesCtrlinTab.InsertItem(0,ItemData1);
    my_tab1->m_myListSeriesCtrlinTab.SetItemText(0, 1, ItemData2);
    my_tab1->m_myListSeriesCtrlinTab.SetItemText(0, 2, ItemData3);

    //my_tab1->m_IconsListCtrl.SetIconToFill(&my_tab1->m_IconsListCtrl);

    my_tab1->m_IconsListCtrl.InsertItem(0,ItemData1);
    my_tab1->m_IconsListCtrl.SetItemText(0, 1, ItemData2);
    my_tab1->m_IconsListCtrl.SetItemText(0, 2, ItemData3);
}

Inthe OnClick of second List Control
void CMyListSeriesResltsCtrl::OnNMClick(NMHDR *pNMHDR, LRESULT
*pResult)
{
    // TODO: Add your control notification handler code here

    *pResult = 0;
    CString strMessage;
    strMessage = "List Series Results Control0-OnNMClick";

// CString strMessage;
    *pResult = 0;
    int nRow = GetNextItem(-1, LVNI_SELECTED);
    strMessage.Format(_T("Row selected is % d "),nRow +1);
    //AfxMessageBox(strMessage);
    CString ItemData1= GetItemText(nRow,0);
    //AfxMessageBox(ItemData1);
    CString ItemData2= GetItemText(nRow,1);
    //AfxMessageBox(ItemData2);
    CString ItemData3= GetItemText(nRow,2);

    ASSERT(my_tab1->m_IconsListCtrl);

    my_tab1->m_IconsListCtrl.InsertItem(0,ItemData1);
    my_tab1->m_IconsListCtrl.SetItemText(0, 1, ItemData2);
    my_tab1->m_IconsListCtrl.SetItemText(0, 2, ItemData3);

}


Bhargs:

And what are the variables in

m_myListSeriesCtrl.SetTabToFill(tab1); First List control of tab
control
m_ResultsCtrl.SetTabToFill(tab1); //Second List control of tab control

??

m_myListSeriesCtrl is the list control on the form view, yes?
What is m_ResultsCtrl?

And aren't these commands supposed to operate on the controls in the
tab? This is not a good design. Whatever these commands are supposed to
accomplish (you do not say), it would be better to call a method of
CTab1 to do it.

You have a very confusing design and nomenclature, and I sense that you
are using the class CMyListSeriesCtrl for two different objects, which
could be a problem as (I think) you are using message reflection.

David Wilkinson

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