Dialog Messages

I want to run some code
after the Dialog Box is initialized
and painted.

I can`t do it in WM_INITDIALOG
beacause the dialog was not painted.

Michael.
michael_telmapAsked:
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nietodConnect With a Mentor Commented:
The dialog is not vet visible when the WM_INITDIALOG message is received.  It is still hidden.  

If you want the code to run after the dialog is first painted, you nedd to look for the WM_PAINT message.  Pass this message on to the default dialog procedure (DefDlgProc()) so that the window is painted, then what the default dialog procedure returns, do your processing.  If your processing needs to be done only the first time the dialog is painted, you can  use some sort of semaphore to insure it is not done every time the windows is repainted.

let me know if you have any questions.
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michael_telmapAuthor Commented:
Could you please send me an Example,
I dont understand exactly how to do it.
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michael_telmapAuthor Commented:
PS: I`m Working with VC6++.
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nietodCommented:
I really don't know what you are doing.....

You woudl have a dialgo procedure with somethign like

BOOL MyDlgProc(HWND WndHnd, UINT Msg,WPARAM WrdPrm,LPARAM LngPrm)
{
    switch (Msg)
   {
       case WM_PAINT:
       {
          DefDlgProc(WndHnd,Msg,WrdPrm,LngPrm);
          // Do something here.
          return TRUE
       }
    }
    return FALSE;
}
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MarkensteinCommented:
If your not going to be hiding the dialog you can use the WM_SHOW message.  This occurs every time the window is set the visible flag to true.  Usually only once.
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nietodCommented:
But that occurs before the dialog is painted (I think), the question said the processing must be done after it is painted (unless that was a mistake.)
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michael_telmapAuthor Commented:
Where should call for MyDlgProc?
How does it work?
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RONSLOWCommented:
At the end of your OnInitDialog (or the code that handles WM_INITDIALOG if your not MFC), post yourself a message (eg a WM_USER or a registered message) and in the handler for that message do whatever it is you want to do.

eg.
in MFC:

static const UINT WM_MYATSTARTOFDIALOG= ::RegisterWindowMessage("MYATSTARTOFDIALOG");

BEGIN_MESSAGE_MAP(CMyDialog, CDialog)
//{{AFX_MSG_MAP(QListCtrl)
  ...
ON_REGISTERED_MESSAGE(WM_MYATSTARTOFDIALOG, OnMyMessage)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

BOOL CMyDialog::OnInitDialog() {
  CDialog::OnInitDialog();
  ...
  PostMessage(WM_MYATSTARTOFDIALOG);
  return TRUE;
}

LRESULT CMyDialog::OnMyMessage(WPARAM wparam, LPARAM lparam) {
  ... whatever ...
}

if not in MFC .. I'd rather not think about it :-) .. but it is not hard.

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nietodCommented:
I don't think that will work, you usually only get WM_PAINT messages when  there are no messages waiting in the message queue, so the message you post will get handled before the WM_PAINT message.  I think.  Its possible that when the window is made visible, a WM_PAINT will be forced earlier, I'm not sure.
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RONSLOWCommented:
One can always do an Invalidate/UpdateWindow or a RedrawWindow to force painting earlier (perhaps at the end of OnInitDialog?)

Infact, that may solw the problem anyway.
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nietodCommented:
>> One can always do an Invalidate/UpdateWindow
>> or a RedrawWindow to force painting earlier
Right.  MY point (question?) is that being done by the OS?  If so then your suggestion will work, other wise it won't because the message you are posting will get handled before the paint.

......Or when, the message is handled, you could force a paint first, is that your point?  That would make sense.

>> (perhaps at the end of OnInitDialog?)
You can't force a paint there, because the dialog is still hidden.  But you could force the paint when the posted message gets handled.
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