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DeferWindowPos doesn't always cause OnSize message

Posted on 2002-07-09
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Last Modified: 2012-08-13
I am using DeferWindowPos to position several child windows (all have same Z-order). I need EndDeferWindowPos to generate an OnSize message each time it is called because I adjust the font based on the window size. It gets called sometimes, but not every time. Any idea why or how to fix it?

   int count = m_PaneList.Count();
   HDWP  hdwp = ::BeginDeferWindowPos(count + 1);

   
   for ( it.First(); it.IsValid(); it.Next() )
   {
      StatusWindowPane* pane = it.Object();
      if ( !pane )
         continue;
     
      pane->SetOrigin(CPoint(rc.left, rc.top));

      if ( hdwp )
            hdwp = ::DeferWindowPos( hdwp, pane->m_hWnd,  NULL, origin.x, origin.y,pane->Width(), rc.Height(),
            SWP_NOZORDER | SWP_NOACTIVATE);

      origin.x += pane->Width();
   }
   if ( hdwp )
      ::EndDeferWindowPos(hdwp);
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Question by:drilene56
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3 Comments
 
LVL 8

Accepted Solution

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fl0yd earned 100 total points
ID: 7150684
If insufficient system resources are available for DeferWindowPos to succeed it returns NULL. In that case you should abandon any further calls to DeferWindowPos and not call EndDeferWindowPos -- your code doesn't do either of those. The MSDN also doesn't guarantee that EndDeferWindowPos generates WM_SIZE-messages -- it generates WM_WINDOWPOSCHANGING- and WM_WINDOWPOSCHANGED-messages for all windows changed.
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by:griessh
ID: 7375942
Dear drilene56

I think you forgot this question. I will ask Community Support to close it unless you finalize it within 7 days. You can always request to keep this question open. But remember, experts can only help you if you provide feedback to their questions.
Unless there is objection or further activity,  I will suggest to accept

     "fl0yd"

comment(s) as an answer.

PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!
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Expert Comment

by:Mindphaser
ID: 7419766
Force accepted

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