Re: Exception Error. - C / C++ / MFC Discussion Boards

FISH78623-Jul-09 5:20

23-Jul-09 5:20

Can Someone help I am not sure whats wrong.

I am getting the following debug message:
First-chance exception at 0x5d0c373e in Capture Data.exe: 0xC0000005: Access violation writing location 0x0043454c.

However on exit I get:
The program '[1284] Capture Data.exe: Native' has exited with code 0 (0x0).
Here is the code I have used:

BOOL CCaptureDataApp::InitInstance()
{
InitCommonControls();
CWinApp::InitInstance();
CCaptureDataSheet sheet("My Very Own Property Sheet App",NULL,0);
sheet.m_psh.dwFlags |= PSH_NOAPPLYNOW;//hide apply button
m_pMainWnd=&sheet;
INT_PTR nResponse=sheet.DoModal();
return FALSE;

In the Capture Data Sheet

IMPLEMENT_DYNAMIC(CCaptureDataSheet, CPropertySheet)
CCaptureDataSheet::CCaptureDataSheet(UINT nIDCaption, CWnd* pParentWnd, UINT iSelectPage)
	:CPropertySheet(nIDCaption, pParentWnd, iSelectPage)
{
	AddPage(&m_Page01);
	AddPage(&m_Page02);
}

CCaptureDataSheet::CCaptureDataSheet(LPCTSTR pszCaption, CWnd* pParentWnd, UINT iSelectPage)
	:CPropertySheet(pszCaption, pParentWnd, iSelectPage)
{
	AddPage(&m_Page01);
	AddPage(&m_Page02);
}

CCaptureDataSheet::~CCaptureDataSheet()
{
}
BOOL CCaptureDataSheet::OnInitDialog()
{
	BOOL bResult = CPropertySheet::OnInitDialog();
}

Re: Exception Error.

Code-o-mat23-Jul-09 6:17

Code-o-mat

23-Jul-09 6:17

I don't know why you get that exception but try turning on "Break into debugger on exceptions" in Visual Studio, it might show you where exactly the exception gets thrown. (In VS2003 it's under Debug->Exceptions in the menu)

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Exception Error.

FISH78623-Jul-09 6:32

FISH786

23-Jul-09 6:32

This is where i am stuck in the debgugger. Not sure whats happening?

BOOL AFXAPI AfxDeactivateActCtx(DWORD dwFlags, ULONG_PTR ulCookie)
{	
	BOOL rc = pfnDeactivateActCtx != 0 ? pfnDeactivateActCtx(dwFlags, ulCookie) : FALSE;
	return rc;
}

Why would it exit with a 0 if I haven't changed anything else in the code?
Would it not give me a memory leak or something?

Re: Exception Error.

FISH78627-Jul-09 3:37

FISH786

27-Jul-09 3:37

http://msdn.microsoft.com/en-us/library/0bw65cxb(VS.80).aspx[^]">

This article states to ignore the return value from the CPropertySheet Class, unless I mis-understood it.

Does that mean I ignore the exception as well?

Re: Exception Error.

Code-o-mat27-Jul-09 3:40

Code-o-mat

27-Jul-09 3:40

Don't know but i doubt it.

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Exception Error.

FISH78628-Jul-09 10:22

FISH786

28-Jul-09 10:22

I am sorry I am not trying to be a pain. This is frustratung me...
Here is what I did...Any suggetions...
On a different machine i went down in versions..from 2008-2005-and finally to VStudio 6.
I used the same steps in all ..I got the same exception error except in Vstudio 6..Where I got no exception error...Imported the same project into my Visual Studio 2008 and it works fine...No First-chance error.

I am not sure what to do?...Well for now I can work with this imported project...but is this really a solution?...I have come to the end of the rope on this one...If I did something wrong, would VStudio 6 not complain as well?

Do you think you can advice me as what to do? I don't like to give up, at the sametime I don't want to be hitting my head if it is a bug in VStudio 2008?

I can't see me to be the only one trying or using the property sheet based application?

Thanks, I will really appreciate some sort of feed back, I am new at this and it's frustrating me..Please advice.

Re: Exception Error.

Code-o-mat28-Jul-09 10:46

Code-o-mat

28-Jul-09 10:46

Is it possible that maybe all your project needed was a complete rebuild?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Exception Error.

FISH78628-Jul-09 11:09

FISH786

28-Jul-09 11:09

I did 3 different projects and with all I did a rebuild..
thinking of the same thing?

Re: Exception Error.

Code-o-mat29-Jul-09 0:24

Code-o-mat

29-Jul-09 0:24

Yes, i am just clueless how importing the very same project from 6.0 would solve your problem...
So you say the exception is thrown from AfxDeactivateActCtx? I supose that the pfnDeactivateActCtx pointer is pointing at something it shouldn't be. Can you maybe try to track down where this gets a value assigned? Maybe whatever it is pointing at gets destroyed somewhere and then the pointer is not NULL-ed out...

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Re: Exception Error.

FISH78629-Jul-09 9:36

FISH786

29-Jul-09 9:36

I am getting it in disassembly.

Re: Exception Error.

Code-o-mat29-Jul-09 9:41

Code-o-mat

29-Jul-09 9:41

Check your callstack untill you see something familiar, otherwise i am out of ideas and without actually seeing this happen i doubt i can do anything to help, sorry Frown | :(

. Maybe someone else has a good idea...

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

How to put something in status bar at first launch ?

mesajflaviu23-Jul-09 3:52

mesajflaviu

23-Jul-09 3:52

I don't know how to set some text in status bar at first application launch because always show "Ready" message ... I mention that my application is SDI but I think that applied on MDI too .I try to do that in twoo way : in CMainFrame::OnCreate : SetMessageText("My message") with no result and m_wndStatusBar.SetPaneText(0,"My message") but in vain. Can you help me ? Thank you.

const in class as a member variable?

sam_psycho23-Jul-09 3:43

sam_psycho

23-Jul-09 3:43

Is it possible to declare member variable of class as a const, if yes,please give me 1 example how to initialize it and if not, why?

Re: const in class as a member variable?

Cedric Moonen23-Jul-09 3:47

Cedric Moonen

23-Jul-09 3:47

Yes, it is possible. You have to initialize it in the constructor initialization list:

MyClass::MyClass() : myConstInt(5) 
{
}

You can also initialize it in the header file too, when declaring it:

class MyClass 
{
   const int myConstInt = 5;
}

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: const in class as a member variable?

sam_psycho23-Jul-09 3:56

sam_psycho

23-Jul-09 3:56

This is working fine

 MyClass::MyClass() : myConstInt(5) 
{
}

but it is not possible,

class MyClass 
{
   const int myConstInt = 5;
}

compiler is giving error,

So I guess only one way to initialize const in a class..

Re: const in class as a member variable?

Cedric Moonen23-Jul-09 3:58

Cedric Moonen

23-Jul-09 3:58

Ooops, my bad. I don't use that notation very often. I thought it was ok but it is only valid if the member is static also.

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: const in class as a member variable?

CPallini23-Jul-09 3:53

CPallini

23-Jul-09 3:53

sam_psycho wrote:
Is it possible to declare member variable of class as a const,

Yes.

sam_psycho wrote:
if yes,please give me 1 example how to initialize it

class A
{
  static const int  c = 299792458;	
  const int a;

  A():a(5){}
};

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]

Re: const in class as a member variable?

sam_psycho23-Jul-09 4:20

sam_psycho

23-Jul-09 4:20

from above discussion I have come to conclusion that compiler does not allow
any type of initialization in class, so statement

static const int  c = 299792458;

in your code also creating problem... Frown | :(

Re: const in class as a member variable?

CPallini23-Jul-09 6:06

CPallini

23-Jul-09 6:06

You're wrong (I'm right, of course... Roll eyes | :rolleyes:

). It looks like you missed the static modifier.
Smile | :)

Re: const in class as a member variable?

sam_psycho23-Jul-09 6:22

sam_psycho

23-Jul-09 6:22

who is lying compiler or you?..but I should believe in compiler and it says that

error: c:\test.cpp 6: cannot initialize class member here

try this code

class temp
{
 static const int i=10;
};
void main()
{
}

Re: const in class as a member variable?

CPallini23-Jul-09 6:50

CPallini

23-Jul-09 6:50

I never lie. Anyway maybe your compiler follows strictly the C++ stanbdard.
(my compiler doesn't complain, see [^]).
Smile | :)

TitleBar

kumar sanghvi23-Jul-09 3:36

kumar sanghvi

23-Jul-09 3:36

Hi,
How can i increase the height of the Title bar of a Dialog based on the font size.....

Re: TitleBar

Mahesh Kulkarni23-Jul-09 20:59

Mahesh Kulkarni

23-Jul-09 20:59

Why this question is repeated?

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

Which low-level I/O API is better? MFC or POSIX

Dimitris Vikeloudas23-Jul-09 3:13

Dimitris Vikeloudas

23-Jul-09 3:13

Few years ago we ported our application low-level to MFC. Instead of using open, read, write etc. we moved to MFC specifics like CreateFile(), ReadFile & WriteFile. We also did the same for the locking functions i.e. use LockFileEx instead of fcntl. Recently we start using WRITE_THROUGH flags everywhere to force direct writing to disk rather than via O.S system cache. Whilst most customers are happy and solved few of their problems some of them still have issues that are hard to track and reproduce. Hence there is a thought to go back to POSIX I/O API but this may creates us again more problems than it solves.

My question is the following: Assuming that we are targeting a Win32 platform (XP and Vista) which I/O is the better low-level I/O it terms of a) performance, b) security of the following choices?
i. MFC specific functions like CreateFile, LockFileEx etc.
ii. POSIX style low-level I/O API like _open(), _fcntl()using a VC++ compiler
iii. POSIX style low-level I/O but this time using a late version gcc/g++ compiler.

If someone has the same dillemas would be nice to hear the views. Also if someone knows any article or comparisons could you please direct me to them?

Thanks.

Re: Which low-level I/O API is better? MFC or POSIX

CPallini23-Jul-09 3:41

CPallini

23-Jul-09 3:41

If you're targetting only Windows then I would (politely) suggest you Win32 API, such as CreateFile, LockFileEx, etc..
Smile | :)

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