C / C++ / MFC

26-Jun-02 5:52

I have a console app that uses MFC. I am doing some testing on a class that I have that utilizes CStdioFile. I know that the CStdioFile constructor will throw an exception if something goes wrong (e.g., it can't create the file.)

I try to catch this exception in the standard manner, and that part seems to work. But when I call its GetErrorMessage function, it triggers an ASSERT deep in MFC code. It appears that it is trying to load a string from a resource, but can't seem to get at the resource.

Below is the relevant fragment of code. I looked at an MSDN article TEAR (I think) and it did the exact same thing - try to call MFC functions from a console app, and I can't see why my code would be any different. (NOTE: I have also tried catching a CFileException instead of a CException, but that caused the same problem.)

try
{
  CStdioFile file(realFileName, CFile::modeCreate | CFile::modeWrite);

  ...
}

catch(CException *e)
{
  TCHAR buff[201];
  bRet = false;
  e->GetErrorMessage(buff, 200);   // <-- THIS LINE ASSERTS!
  TRACE("Writing to file %s failed:\n\t%s", fileName, buff);
  e->Delete();
}

Also, in my main function, this is how I initialize MFC (appwizard generated code):

// initialize MFC and print and error on failure
if(!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
{
  // TODO: change error code to suit your needs
  cerr << _T("Fatal Error: MFC initialization failed") << endl;
  return 1;
}

Even if you win the rat race, you're still a rat.

Joaquín M López Muñoz26-Jun-02 7:13

Joaquín M López Muñoz

26-Jun-02 7:13

You'll have to do a little hacking to get MFC to work in a console app. In this case, chances are the lacking of a CWinApp object in your code is driving MFC nuts in its effort to locate the appropriate resources. Try declaring a CWinApp object to see it that works.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Navin26-Jun-02 7:20

26-Jun-02 7:20

Nope - already got a CWinApp object.

I could just ignore this, since this app is really just a test harness, and our "real" apps are full MFC (either doc-view or dialog based), not console apps. But I want it to work right! Roll eyes | :rolleyes:

Even if you win the rat race, you're still a rat.

Joaquín M López Muñoz26-Jun-02 7:52

Joaquín M López Muñoz

26-Jun-02 7:52

Have you called CWinApp::InitInstance? Which is the particular ASSERT that is failing?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Navin26-Jun-02 8:03

26-Jun-02 8:03

Explicitly calling InitInstance didn't help.

The assert that fails, fails from CException::GetErrorMessage. Somewehre, some function calls AfxFormatStrings, which asserts after a call to AfxLoadString fails.

I guess I'll have to pour through a dialog-based or doc-view app, check out all the things that it does, and do some "emperical programming" until I find the combo that works... Cry | :((

Even if you win the rat race, you're still a rat.

AHA!

Navin26-Jun-02 8:16

Ms Word Automation margins

26-Jun-02 8:16

Figured it out. I needed to have
#include "afxres.rc"
in my resource includes. Even though this gets put there automatically by AppWizard in an MFC app, it does NOT get put there automatically when you have a console app, even if you check "An app that supports MFC". Mad | :mad:

Guess that's what I get for relying too heavily on generated code. Blush | :O

Even if you win the rat race, you're still a rat.

Braulio Dez26-Jun-02 5:47

Braulio Dez

26-Jun-02 5:47

Hi,

I want to know what is the useful space that I have in a document ( the X-Axis of the page)...

My idea is before insert one ActiveX scale it to the optimal size in the Ms Word instance.

Thanks in advance, greetings
Braulio

SAFEARRAY in Variant

Hans Ruck26-Jun-02 5:43

Hans Ruck

26-Jun-02 5:43

I pass a SAFEARRAY through a Variant from an ATL-made COM to some VB testing program.
Now i have the Variant and i don't know how to extract the SAFEARRAY from it.

rechi

Re: SAFEARRAY in Variant

Jeremy Falcon26-Jun-02 5:48

26-Jun-02 5:48

This is the second time you cross-posted! You said it wasn't a common thing for you to do. Confess, you're Satan aren't you? OMG | :OMG:

Jeremy L. Falcon<nobr>
Homepage : Sonork = 100.16311

"But everybody darlin' sometimes bites the hand that feeds."
"Remember in this game we call life that no one said it's fair."
"Just because you're winnin' don't mean you're the lucky ones."
Song: Breakdown - Album: Use Your Illusion II - Artist: Guns N' Roses

Re: SAFEARRAY in Variant

Hans Ruck26-Jun-02 5:59

Hans Ruck

26-Jun-02 5:59

I don't hate satan, if this is what you wanna' hear.
The cross-posting is the result of the weak probability of getting some answer on the other forums.
Why are you so angry about cross-posting? Confused | :confused:

rechi

Re: SAFEARRAY in Variant

Jeremy Falcon26-Jun-02 6:17

26-Jun-02 6:17

Bogdan Rechi wrote:
I don't hate satan, if this is what you wanna' hear.

I don't believe in him. Poke tongue | ;-P

It was a joke.

Bogdan Rechi wrote:
Why are you so angry about cross-posting?

I'm not angry at all. I just think you're Satan. Smile | :)

BTW, it is not proper netiquette to cross-post. The reason why is that we don't owe you anything. We choose to help. Don't pester us with a request over and over again just because it's not answered a couple minutes after you ask it. You'll find this holds true everywhere on the Internet and not just CP.

Jeremy L. Falcon<nobr>
Homepage : Sonork = 100.16311

"But everybody darlin' sometimes bites the hand that feeds."
"Remember in this game we call life that no one said it's fair."
"Just because you're winnin' don't mean you're the lucky ones."
Song: Breakdown - Album: Use Your Illusion II - Artist: Guns N' Roses

Mutex

Anthony988726-Jun-02 5:38

Anthony9887

26-Jun-02 5:38

I'm using a mutex object to check if a dialogbox application is running. I want to know how to call ShowWindow from the InitInstance to force the dialogbox to the foreground.

Thanks

Navin26-Jun-02 5:44

26-Jun-02 5:44

There is a really good article by Joseph M. Newcomer that deals with exactly what you're trying to do.

Avoiding Multiple Instances of an Application

Even if you win the rat race, you're still a rat.

Jeremy Falcon26-Jun-02 5:45

26-Jun-02 5:45

You can call SetForegroundWindow() or SetWindowPos() to do that.

Jeremy L. Falcon<nobr>
Homepage : Sonork = 100.16311

"But everybody darlin' sometimes bites the hand that feeds."
"Remember in this game we call life that no one said it's fair."
"Just because you're winnin' don't mean you're the lucky ones."
Song: Breakdown - Album: Use Your Illusion II - Artist: Guns N' Roses

Dean Michaud26-Jun-02 7:05

Dean Michaud

26-Jun-02 7:05

Don't use SetForegroundWindow(), it behaves differently in WinXP than in previous iterations of Windows.

Check this silimar thread out too for reference:
http://www.codeproject.com/script/comments/forums.asp?msg=217904&forumid=1647#xx217904xx

: Dean 'Karnatos' Michaud

Jeremy Falcon26-Jun-02 7:23

26-Jun-02 7:23

Thanks for the info!

Jeremy L. Falcon<nobr>
Homepage : Sonork = 100.16311

"But everybody darlin' sometimes bites the hand that feeds."
"Remember in this game we call life that no one said it's fair."
"Just because you're winnin' don't mean you're the lucky ones."
Song: Breakdown - Album: Use Your Illusion II - Artist: Guns N' Roses

Scott H. Settlemier27-Jun-02 9:04

Scott H. Settlemier

27-Jun-02 9:04

I assume you want to quit the current dialog and bring
the existing dialog to the foreground.

SetForegroundWindow is the right call, but its behavior
in later versions of Windows will thwart you (it just
flashes the item on the taskbar) unless you jump the
right hoops: AttachThreadInput

Here's a great article :
http://www.etree.com/tech/Articles/attachthreadinput.pdf

And here's some code to do it:

DWORD MyThreadId=GetCurrentThreadId();
DWORD ForeThreadId=::GetWindowThreadProcessId(::GetForegroundWindow(),0);

HWND hForegroundMe=0;
// Get handle to the window you want to place in the foreground.
// For instance use EnumThreadWindows if you know the ThreadId
// (perhaps you have it saved in a shared memory?)
// or use EnumWindows if you know the window text of the window
// you are looking for...

if (GetWindowLong(hForegroundMe,GWL_STYLE)&WS_MINIMIZE)
::ShowWindow(hForegroundMe,SW_RESTORE),::UpdateWindow(hForegroundMe);
if (ForeThreadId!=MyThreadId)
AttachThreadInput(ForeThreadId,MyThreadId,TRUE);
::SetForegroundWindow(hForegroundMe);
if (ForeThreadId!=MyThreadId)
AttachThreadInput(ForeThreadId,MyThreadId,FALSE);

Form objects limit

RuiSantiago26-Jun-02 5:27

RuiSantiago

26-Jun-02 5:27

Hi, i'm dealing with a form with about 250 objects, now i cannot insert any other objects. Is there a limit for objects in a form, can i solve by code?

Thank you

benjymous26-Jun-02 5:32

benjymous

26-Jun-02 5:32

Do all the objects need to be on the same form, or just all be displayed?
You could use property pages to split up the objects, and then display multiple property pages

--
Help me! I'm turning into a grapefruit!

Roger Allen26-Jun-02 5:37

Roger Allen

26-Jun-02 5:37

If I recall, there is an artificial limit of around 255 controls per window. It may be OS based or editor based. Just can't remember.

As Benjymous said, splitting up the controls onto sub-pages may be the best way to go.

Roger Allen
Sonork 100.10016

If I had a quote, it would be a very good one.

RuiSantiago26-Jun-02 5:44

RuiSantiago

26-Jun-02 5:44

Well, i'm kind of new with Visual C++, i understand the function of DoDataExchange, i read a bit about DDP in MDSN, i understand the concept but i'm sure that i know how to use it, can you give me a example?

Most of my objects are used with an array, and for this form i don't have a ClassWizard, i've got a parse error when i try to call it, but the aplication works.

Thank you all