Re: AFX_MANAGE_STATE() macro disturbs the startup position of the ATL dialog

From:

"David Ching" <dc@remove-this.dcsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 14 Jan 2010 19:09:50 -0800

Message-ID:

<uh06zAZlKHA.3476@TK2MSFTNGP06.phx.gbl>

"Santi" <santoshpill@gmail.com> wrote in message
news:0e33157b-c1bf-4a9b-ba3c-dc313e824266@o28g2000yqh.googlegroups.com...

On click of one of its buttons, the MFC dialog application,
instantiates the COM component and invokes the ISum::Add() method.
This displays the ATL dialog CAcceptInput. The ATL dialog appears in
the center of its parent window .i.e. the MFC dialog but if an
AFX_MANAGE_STATE() macro is introduced in the Add() method (as shown
below) then the ATL dialog does NOT appear in the center rather it is
LEFT aligned to its parent window .i.e. the MFC dialog.

STDMETHODIMP CSum::Add()
{
    AFX_MANAGE_STATE(AfxGetStaticModuleState())

    CAcceptInput dlg;
    dlg.DoModal();
    return S_OK;
}

I have verified that adding AFX_MANAGE_STATE() macro does NOT
    1. Change the parent of the ATL dialog.
    2. Change the window style & extended window style.

If the parent window to the dialog is not specified, MFC assumes it is
CWinApp::m_pMainWnd. Apparently that is being changed with
AFX_MANAGE_STATE. Why don't you try to specify the parent window to
CAcceptInput by:

CAcceptInput dlg(pParentWindow); // <-- will this work?

Also I debugged the OnInitDialog() method of the ATL dialog and
checked the position of the dialog, to my surprise in both the
scenarios the position was the same. Its only after the WM_INITDIALOG
and just before the display of the ATL dialog that the position gets
changed in case of the AFX_MANAGE_STATE() macro.

I am unable to understand why the ATL dialog is getting impacted with
the AFX_MANAGE_STATE() macro though there is no relationship between
them.

Can anybody provide any help on this?

MFC accomplishes the centering by using a hook (WH_CBT, I believe).

-- David