Re: How do I display an image as the background in CMDIFrameWnd

From:
"Tom Serface" <tom.nospam@camaswood.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Thu, 22 Mar 2007 12:24:24 -0700
Message-ID:
<C790C28A-0129-4123-9D8F-35F60173BC1A@microsoft.com>
Here's a link with a couple of ideas on how to do it:

http://www.codeguru.com/forum/showthread.php?t=319786

Tom

"Bruce" <bwolven@nospam.nospam> wrote in message
news:u0VREWLbHHA.960@TK2MSFTNGP03.phx.gbl...

I saw this example but it didn't make sense to me.

Why does the erase background on the child window paint the frame?

I'm not trying to change the background of the client window that gets
open, only the MDI frame window.

If that's the way it must be done, why can't I just add a WM_ERASEBKGND
handler to the child class to do the same thing?

Is the framework getting in the way?

Also, will this method work with VS2005 since we are in the process of
moving our source to it?

--
Thanks,
Bruce

"AliR (VC++ MVP)" <AliR@online.nospam> wrote in message
news:FgzMh.521$rO7.19@newssvr25.news.prodigy.net...

You will have to subclass the m_hWndMDIClient of the CMDIFrameWnd with
your own window and then catch the WM_ERASEBKGND and WM_PAINT messages
there.

So create class that inherits from CWnd, lets call it CClientWnd. Then
subclass m_hWndMIDClient in the Frame's OnCreateClient method. Take over
the WM_ERASEBKGND message and paint your bitmap there and return TRUE.
If you bitmap won't takeup the entire client area then you might want to
it in WM_PAINT.

class CClientWnd : public CWnd
{
  DECLARE_DYNAMIC(CClientWnd)

public:
  CClientWnd();
  virtual ~CClientWnd();

protected:
  DECLARE_MESSAGE_MAP()
public:
  afx_msg BOOL OnEraseBkgnd(CDC* pDC);
};

BEGIN_MESSAGE_MAP(CClientWnd, CWnd)
  ON_WM_ERASEBKGND()
END_MESSAGE_MAP()

BOOL CClientWnd::OnEraseBkgnd(CDC* pDC)
{
  //draw bitmap here
  pDC->BitBlt(....);

  return TRUE;
}

class CMainFrame : public CMDIFrameWnd
{
private:
  CClientWnd m_Client;
};

BOOL CMainFrame::OnCreateClient(LPCREATESTRUCT lpcs, CCreateContext*
pContext)
{
  if (CMDIFrameWnd::OnCreateClient(lpcs, pContext))
  {
     m_Client.SubclassWindow(m_hWndMDIClient);
     return TRUE;
  }
  return FALSE;
}

AliR.

"Bruce" <bwolven@nospam.nospam> wrote in message
news:uEi4fKKbHHA.4720@TK2MSFTNGP04.phx.gbl...

I have a VC++ MFC 7.1 application and I am looking for a way to display a
background image in the application's frame window behind any child
windows that may be displayed. It is a CMDIFrameWnd derived class.

I have found a couple of examples that are to change the background
color in the CMyMDIFrameWnd::OnEraseBkgnd() handler.

But it doesn't seem to work. The background color always remains the
same.

Is there something that I am missing?

I am running on Windows XP Professional.
--
Thanks,
Bruce

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