Re: trying to get active view pointer from cmainframe

From:

"harshalshete@gmail.com" <harshalshete@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

24 May 2006 05:30:04 -0700

Message-ID:

<1148473803.714942.211440@y43g2000cwc.googlegroups.com>

MDIGetActive()
i checked the code API internally

checking mdiclient is not null
then it is using sendmessage function to get the handle of active child
window
then it uses CWnd::FromHandle()

CMDIChildWnd* pWnd = (CMDIChildWnd*)CWnd::FromHandle(hWnd);
ASSERT(pWnd == NULL ||
pWnd->IsKindOf(RUNTIME_CLASS(CMDIChildWnd)));//and //here it asserts

why here it is asserting.
if it is getting handle to the child window then what is the problem?

//for convenience here is code of MDIGetActive
CMDIChildWnd* CMDIFrameWnd::MDIGetActive(BOOL* pbMaximized) const
{
    // check first for MDI client window not created
    if (m_hWndMDIClient == NULL)
    {
        if (pbMaximized != NULL)
            *pbMaximized = FALSE;
        return NULL;
    }

    // MDI client has been created, get active MDI child
    HWND hWnd = (HWND)::SendMessage(m_hWndMDIClient, WM_MDIGETACTIVE, 0,
        (LPARAM)pbMaximized);
    CMDIChildWnd* pWnd = (CMDIChildWnd*)CWnd::FromHandle(hWnd);
    ASSERT(pWnd == NULL || pWnd->IsKindOf(RUNTIME_CLASS(CMDIChildWnd)));

    // check for special pseudo-inactive state
    if (pWnd != NULL && pWnd->m_bPseudoInactive &&
        (pWnd->GetStyle() & WS_VISIBLE) == 0)
    {
        // Window is hidden, active, but m_bPseudoInactive -- return NULL
        pWnd = NULL;
        // Ignore maximized flag if pseudo-inactive and maximized
        if (pbMaximized != NULL)
            *pbMaximized = FALSE;
    }
    return pWnd;
}

when i debugged this code it shows me that hwnd of child is not null
means it is getting child window's handle so why it is asserting

Thanks & regards
Harshal shete