C / C++ / MFC

29-May-09 7:15

I am trying to understand how to write an efficient OnPaint routine. That is, I want my routine
to only update the part of the screen that needs to be updated. Therefore I wrote a simple program
that creates a window and displays three lines. Below is the OnPaint routine for that program:

void<br />
CMainWindow::OnPaint()<br />
{<br />
	CPaintDC dc(this);<br />
<br />
	RECT rect1;<br />
	BOOL retValue = GetUpdateRect( &rect1 );<br />
	if ( retValue != 0 ) {<br />
		char *ptr = 0;<br />
		*ptr = 23;<br />
	}<br />
	dc.BitBlt( 0, 0, maxX, maxY, &m_memDC, 0, 0, SRCCOPY );<br />
}

The code works but the routine GetUpdateRect always returns 0. I am wondering if the only way to
get GetUpdateRect to return non-zero is if the program sends (via something like SendMessage)
the WM_PAINT message.

You should also observe that in the current code, if GetUpdateRect does return a non-zero value
then the program crashes. Currently, the program never crashes.

Bob

CPallini29-May-09 7:39

CPallini

29-May-09 7:39

BobInNJ wrote:
CPaintDC dc(this);

RECT rect1;
BOOL retValue = GetUpdateRect( &rect1 );

try the statement sequence in the following order:

RECT rect1;
BOOL retValue = GetUpdateRect( &rect1 );

CPaintDC dc(this);

Because, from documentation [^]:

BeginPaint automatically validates the update region, so any call to GetUpdateRect made immediately after the call to BeginPaint retrieves an empty update region.

(CPaintDC constructor eventually calls BeginPaint).
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

BobInNJ29-May-09 9:30

29-May-09 9:30

Thanks for your response. I now understand what is going on.

Bob

David Crow6-Nov-09 17:23

David Crow

6-Nov-09 17:23

I'm doing something very similar but in OnDraw() instead. GetUpdateRect() always returns an empty region. It's an SDI application. Any clues?

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CPallini7-Nov-09 11:23

CPallini

7-Nov-09 11:23

Since the CPaintDC is created in the view OnPaint method (that in turn calls OnDraw), I think you've to override OnPaint, for instance:

void MyView::OnPaint()
{
   GetUpdateRect(&m_rc);
   CPaintDC dc(this); // device context for painting
   OnPrepareDC(&dc);
   OnDraw(&dc);
}

Michael Dunn30-May-09 18:44

Michael Dunn

30-May-09 18:44

You can get the same info from dc.m_ps.rcPaint as well.

--Mike--
Dunder-Mifflin, this is Pam.

BobInNJ31-May-09 4:13

Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

31-May-09 4:13

Mike,

Thanks for the response. I noticed that the item you mentioned gives me exactly what I want
and therefore it is very useful. However, m_ps is a public data member of the class. Therefore,
I do not like the idea of using public data. Is using public data such a bad idea? I am not sure.

Bob

SetwindowPos problem

extreme00129-May-09 6:09

extreme001

29-May-09 6:09

Hi gurus!

I coded an app that searches for another window to overlay it. I used SetLayeredWindowAttributes to make a color transparent in my window. When the the window with right handle was found i want to set place my window over it. For that i created a timer that runs every 10ms. To place my window over the other i used

::SetWindowPos(hndWin, hndOverlayWin, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE);

That works. But when hndWin (that one that should be overlayed) is in background of another window...and i click in hndwin it shortly flickers and the it's send back to background. But when i click a control in my overlaying transparent window the underlying window comes to front. But not if i click an area in the window that's overlayed.

The next thing is that the overlayed window is minimized and clicked in the taksbar, both windows should appear in front.

I'm happy if someone can help!!!

Thank you!

Mark C. Malburg29-May-09 5:19

Mark C. Malburg

29-May-09 5:19

Has anybody experienced this?

I just installed IE 8 and Vista SP2. I'm supporting several VC++ 6.0 (MFC) projects and need to keep it alive on my system.

Now that these are installed, I can open workspaces and recent files, however if I select File-Open in Visual C++ I get nothing (no dialog). If I do it a couple more times VC++ crashes and closes. If I try using the toolbar or "Ctrl-O", VC++ crashes immediately.

Help!

- Mark

Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

BobInNJ29-May-09 6:56

[OT] Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

29-May-09 6:56

Mark,

I am thinking that the version of VC++ 6.0 that is installed on your machine was damaged or
altered by the installation of IE 8 or Vista SP2. This could be related to a new version of a DLL.
I would address this issue by reinstalling VC++ 6.0.

Bob

David Crow29-May-09 7:36

David Crow

29-May-09 7:36

Mark C. Malburg wrote:
I just installed IE 8 and Vista SP2. I'm supporting several VC++ 6.0 (MFC) projects and need to keep it alive on my system.

All the more reason not to mess with a stable system.

Re: [OT] Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

Mark C. Malburg29-May-09 8:13

Mark C. Malburg

29-May-09 8:13

True. I did get some significant improvement out of Outlook and the operating system in general. But I seem to be paying the price with my 11 year old IDE. Wink | ;)

Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

Joe Woodbury29-May-09 13:30

Joe Woodbury

29-May-09 13:30

Perhaps MFC DLL hell?

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

bodhi rayo11-Oct-10 7:24

bodhi rayo

11-Oct-10 7:24

I had the same problem under XP.
I installed SP6 for VC++ and it fixed the problem. Smile | :)

Google: Visual C++ 6.0 service pack 6 download

Re: Visual C++ 6.0 - can't "File Open" after IE 8 and Vista SP2

Mark C. Malburg11-Oct-10 8:09

Mark C. Malburg

11-Oct-10 8:09

Thanks! That's brought it back. Life is good again.

CRichtEditView Vertical Auto Scrolling

susanne129-May-09 4:50

susanne1

29-May-09 4:50

Hallo friends,

I need to enable the auto scrolling feature in my CRichEditView SDI Application , that i must not everytime scroll down with the mouse, please help.

i use the following code in CTest_View.cpp but it did not work:// class CTest_View: public CRichEditView

BOOL CTest_View::PreCreateWindow(CREATESTRUCT& cs)
{
cs.style &=~ (ECO_AUTOHSCROLL | ECO_AUTOVSCROLL);
cs.style |= (WS_HSCROLL | WS_VSCROLL);
cs.style |= (ES_MULTILINE | WS_HSCROLL | WS_VSCROLL | ES_DISABLENOSCROLL);
return CRichEditView::PreCreateWindow(cs);
}

Why the caret of edit control disappeared when it was associated the class encapsulated with my own dll built with CEdit?

bdwzz29-May-09 4:05

bdwzz

29-May-09 4:05

Source code is following:

<br />
/*Header file*/<br />
#pragma once<br />
#include "afxwin.h"<br />
<br />
<br />
// CSuiBianEdit<br />
<br />
class AFX_EXT_CLASS CSuiBianEdit : public CEdit<br />
{<br />
	DECLARE_DYNAMIC(CSuiBianEdit)<br />
<br />
public:<br />
	CSuiBianEdit();<br />
	virtual ~CSuiBianEdit();<br />
<br />
protected:<br />
	DECLARE_MESSAGE_MAP()<br />
};<br />
<br />
<br />
/*Source file*/<br />
#include "stdafx.h"<br />
#include "SuiBianEdit.h"<br />
#include ".\suibianedit.h"<br />
<br />
<br />
// CSuiBianEdit<br />
<br />
IMPLEMENT_DYNAMIC(CSuiBianEdit, CEdit)<br />
CSuiBianEdit::CSuiBianEdit()<br />
{<br />
}<br />
<br />
CSuiBianEdit::~CSuiBianEdit()<br />
{<br />
}<br />
<br />
<br />
BEGIN_MESSAGE_MAP(CSuiBianEdit, CEdit)<br />
END_MESSAGE_MAP()<br />
<br />

C + + by diary

anassamar29-May-09 3:12

anassamar

29-May-09 3:12

Is it possible to write a program in C + + by means of the diary?

thank you
soso

Michael Schubert29-May-09 3:21

Michael Schubert

29-May-09 3:21

You mean you want to use your diary to write a program?

anassamar1-Jun-09 10:57

anassamar

1-Jun-09 10:57

yes, I want to use my diary to write a program (C++ Code),how Do I do?
thanks

thank you
soso

Michael Schubert1-Jun-09 13:02

Michael Schubert

1-Jun-09 13:02

1. Make sure that your diary has all the necessary libraries. You'll find these under December 12th

2. Your diary has to be ISO/IEC 14882:2003 compliant. Note: Pink diaries are not compliant (besides, only girls use these)

3. The compiler that comes with your diary must not put any secrets into the compiled binaries. Please check with your local diary dealer.

Once these specs are met you're good to go!