C / C++ / MFC

CMyMainFrame is the parent window of the dialog, dialog bar with ListBox.
I guess that ListBox is the same child level of the dialog bar since ListBox is declared
at CMyMainFrame class?

m_sCurSelectedString is always updated if the user updates the selection of ListBox.
So, when the dialog is opened, m_sCurSelectedString compares the string in ComboBox
in OnInitDialog().

So, how do we access m_sCurSelectedString from Dialog Box?
1) Pass the parent's CWnd of dialog constructor arguement. or
2) Use CWnd::GetParent() or
3) Use AfxGetMainWnd() and cast the pointer of CMyMainFrame.

And, how do we update m_sCurSelectedString of ListBox.
I think that we can use MessageMap of ListBox in CMyMainFrame.

The other way is that we can pass CWnd of ListBox on Dialog Bar
to the consturctor arguemnt of CMyDialog.
At this case, we can direclty access the currnet selected item of ListBox.:cool: 

extern CMyApp theApp;

private:
    CMainFrame* m_pMainFrame;
public:
    CMainFrame* GetMainFramePtr() { return m_pMainFrame);

m_pMainFrame = pMainFrame;

int CMainFrame::FillComboBox(CComboBox* pCombo)
{
    // fill the combo box
    // and return the number of things you put in it
    return pCombo->GetCount();
}

theApp.GetMainFrame()->FillComboBox(&m_ctrlComboBox);