Problems deserializing an object - C / C++ / MFC Discussion Boards

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C++ Memory Allocation a real headache

Blade Runner19-Jul-02 4:07

Blade Runner

19-Jul-02 4:07

Hi in my application I call GlobalMemoryStatus() to get the status of the virtual memory of my system. It returns the fact I have loads of virtual memory, Great!!. However when I call new() to try to allocate memory that is less then the virtual memory (allocating quite a large amount but still less then the virtual memory)it is returning NULL due to there not being enough memory available.

Does anyone have an explanation for why this is happening?

Thanks

The Blade Runner

Re: C++ Memory Allocation a real headache

Ravi Bhavnani19-Jul-02 4:19

Ravi Bhavnani

19-Jul-02 4:19

Memory allocation will fail if you don't have the required amount of contiguous memory available. Try running my product MemWatcher (free download) and see if that helps. Sorry for the shameless plug, but I think it may help you.

/ravi

Let's put "civil" back into "civilization"
http://www.ravib.com
ravib@ravib.com

Re: C++ Memory Allocation a real headache

Blade Runner19-Jul-02 4:39

Blade Runner

19-Jul-02 4:39

This program only shows whats in Physical memory not virtual memory aswell. I know to memory I am trying to allocate is greater the just the physical memory but the virtual memory according to this GlobalMemoryStatus function shows it is big enough too allocate the memory.

Thanks anyway.

The Blade Runner

Re: C++ Memory Allocation a real headache

Ravi Bhavnani19-Jul-02 4:47

Ravi Bhavnani

19-Jul-02 4:47

MemWatcher can free up memory that Windows mistakenly continues to flag as "in use", thereby possibly allowing more memory to be used by your program. However, if you try to allocate "x" bytes and there aren't "x" contiguous bytes available, the allocation will fail.

Unfortunately, simply increasing your virtual memory won't guarantee that it's actually usable, since none of the data currently in physical memory may be swappable.

/ravi

Let's put "civil" back into "civilization"
http://www.ravib.com
ravib@ravib.com

Ms Word ATL ActiveX print size problem

Braulio Dez19-Jul-02 3:55

Braulio Dez

19-Jul-02 3:55

Hi,

I have developed an ActiveX control using ATL, when I insert it and work with it in Ms Word 2000 it works perfect, but when I print it, depending on the screen resolution, the Word text is printed inside the control or in the right place or shifted Frown | :-(

I have tried the same in Word 2002 and it works fine. How can I fix this ? Is there any well know bug from ATL/Ms Word about this issue ?.

Thanks in advance
Braulio

How to use rebar Chevrons in WTL?

generic_user_id19-Jul-02 3:36

generic_user_id

19-Jul-02 3:36

For some reason I get a compiler error when I try to use chevrons in WTL. I define _WIN32_IE as 0x0500 (instead of 0x0400), but then I get the following error.

c:\...\wtl70\include\atlframe.h(274) : error C2146: syntax error : missing ';' before identifier 'lpnm'

I have IE version 6, I got VC 6 with service pack 4, and I got WTL 7.

What more do I need to get it working? As it looks like I'm missing a header file.

Any ideas? Thanks in advance

- Griffith

Everything you say will be misquoted, ripped out of context and used against you.

Re: How to use rebar Chevrons in WTL?

JohnnyG20-Jul-02 18:43

JohnnyG

20-Jul-02 18:43

I just tried this today and got the same error. Unfortunately, I do not know why either. I think (but am not sure) that maybe WTL7 is for .Net and that is why it may not work. I believe that there is an ATL 2.0, ATL 3.0 and 7.0 and a WTL 3.0 and WTL 7.0. The only thing I can figure, since there seems to be a major jump in version numbers, is that 7.0 is for .Net.

Can someone clarify or verify this?

Problems deserializing an object

Mike Puddephat19-Jul-02 3:23

Mike Puddephat

19-Jul-02 3:23

Hi,

I am in the process of converting all my MFC projects from VS6 to VS.Net and I'm getting a peculiar problem. My programs seemed to convert fine (with a few minor code changes). However, when I run my app it turns out I am having problems deserializing an object of a type of class defined in an extension DLL. I get the following TRACE output "Warning: Cannot load CMyClass from archive. Class not defined".

On the MSDN, it says that this will be a problem when using an extension DLL from a regular DLL. However, I am using the extension DLL from a regular MFC application - which the MSDN says should work fine.

MSDN link here (New window)

Does anyone have any idea why I am getting this error? I would be very grateful if anyone could shed some light on this issue.

Many thanks,

Mike.

C++ syntax question

pankajdaga19-Jul-02 3:17

pankajdaga

19-Jul-02 3:17

I was going through some C++ code and found this syntax:

Complex **_W;

I do not understand the ** notation. Is it a pointer to a pointer? How am I supposed to initialize such an object and access its member functions?

Thanks. Looking forward to some replies Smile | :)

Pankaj

Without struggle, there is no progress

Re: C++ syntax question

Mike Upton19-Jul-02 3:32

Mike Upton

19-Jul-02 3:32

Complex W;
Complex* pW = &W;
Complex** ppW = &pW;
//To dereference
Complex*pX = *ppW;
Complex X=**ppW;
//To access a member function (just guessing at the name of the member!)
double i=(*ppW)->i;
double j=(**ppW).j;

Easy really!

"We are the knights who say Ni" _{(The Knights Who Say Ni)}

Re: C++ syntax question

Christian Graus19-Jul-02 3:33

Christian Graus

19-Jul-02 3:33

pankajdaga wrote:
Is it a pointer to a pointer?

Yes.

pankajdaga wrote:
How am I supposed to initialize such an object and access its member functions?

_W x;
*x = new Complex();
*x->ComplexMethod1();

Christian

come on all you MS suckups, defend your sugar-daddy now. - Chris Losinger - 11/07/2002

Re: C++ syntax question

Mike Puddephat19-Jul-02 3:35

Mike Puddephat

19-Jul-02 3:35

Hi,

I might not be the best at explaining this, but I'll try...

If you want to change a variable that is passed in to a function, you would pass it by pointer or by reference. In the same way, if you want to change a pointer that is passed in to a function, you could pass a pointer to a pointer.

Here is how you might do it:

// We hope that calling FindComplex will change the value of pFoo
Complex* pFoo = NULL;

// Pass a pointer to a pointer
FindComplex(&pFoo);

// Now pFoo may have changed
BOOL bChanged = (pFoo != NULL);

...

void FindComplex(Complex** pFoo)
{
Complex* pFound = NULL;

// Do some code here to find a Complex object and set pFound

*pFoo = pFound;
}

Hope this helps and I hope it's right!!
Smile | :)

Drawing strings on GDI+ that are vertical bottom to top aligned!

Williams19-Jul-02 3:04

Williams

19-Jul-02 3:04

Hi,

How can I draw strings with GDI+ that are are vertical bottom to top aligned!
I try things as SetFormat(StringFormatFlagsDirectionVertical | StringFormatFlagsDirectionRightToLeft) but the text is always top to bottom oriented.

Rotate the text, yourself

Jonathan de Halleux19-Jul-02 5:16

Jonathan de Halleux

19-Jul-02 5:16

Yep, that's a serious limitation of GDI+ but it can be easily overpassed by rotating yourself the text:

// defined somewhere
Graphics* m_pGraphics;

What you have to do is :
1. translate text to origin,
2. rotate,
3. translate back to position,

Let's go:
We create a graphic container to apply transformations

graphicsContainer = m_pGraphics->BeginContainer();

Doing steps 1,2,3 the order of matrix multiplication is important !

m_pGraphics->TranslateTransform(pointF.X,pointF.Y);
// angle is the angle you want to rotate your text in CCW turn with 0 = horizontal. Of course, in GDI+, Microsoft uses
// CW angle so it is not compatible with trigonometric functions :(
m_pGraphics->RotateTransform(-angle);
m_pGraphics->TranslateTransform(-pointF.X,-pointF.Y);

Draw the string

m_pGraphics->DrawString(str, -1, &font, pointF, &sf,&solidBrush);

Fold back transformations by getting out of the container

m_pGraphics->EndContainer(graphicsContainer);

Jonathan de Halleux, Belgium.

Re: Rotate the text, yourself

Williams19-Jul-02 5:33

Williams

19-Jul-02 5:33

Very thanks friend.
It´s really what I was thinking to do. Thanks for your help! Smile | :)

single instance

slah19-Jul-02 2:43

slah

19-Jul-02 2:43

i am using winmain in my application and i want to restrict that only one instance of the application should run at one time. is there way to restrict it.

Re: single instance

Mike Upton19-Jul-02 3:09

Mike Upton

19-Jul-02 3:09

Look at this^{^} article.

"We are the knights who say Ni" _{(The Knights Who Say Ni)}

Re: single instance

Raphael Kindt19-Jul-02 3:12

Raphael Kindt

19-Jul-02 3:12

Perhaps this article can help you ...
Clic here
A single instance is a "Singleton" Smile | :)

Hello World!!! Smile | :)

from Raphaël

Re: single instance

Mike Upton19-Jul-02 3:46

Mike Upton

19-Jul-02 3:46

Sorry, but a Singleton is to do with having a single instance of a particular class in an application (and is a very useful thing Wink | ;)

), but the question was asking about only ever having a single instance of an application running at a time.

"We are the knights who say Ni" _{(The Knights Who Say Ni)}

Re: single instance

Raphael Kindt19-Jul-02 5:18

Raphael Kindt

19-Jul-02 5:18

Of course... Sorry...
Blush | :O

Hello World!!! Smile | :)

from Raphaël

PIC C interrupt using #int_global

Lucky the code machine19-Jul-02 2:14

Lucky the code machine

19-Jul-02 2:14

Hi all, I know this is cheeky in the C++ section but pleeease help me!! I need to shave some time off of the compiler generated interrupt code. In the code below (#int_gobal with compiler generated interrupt code within it) this shoul compile then work the same as it previously did but the compiler stops on '03.5', this is the status register bit 5 so i tryed 'BTFSC STATUS,5' but that didnt work either. Im very confused, please help me.

#int_global
isr() { // Will be programmed at location 4
#asm
BTFSC 03.5
GOTO 00A
MOVWF 25
SWAPF 03,W
MOVWF 26
GOTO 00F
........ etc ....
#endasm
}
Cry | :((

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

Re: PIC C interrupt using #int_global

Rage19-Jul-02 2:43

Rage

19-Jul-02 2:43

i duuno much about PICs, but other controlers ... so ... first, why not doing all the stuff in asm ? ... secondly, giving 03 will always work whereas STATUS must be an alias and should be used only if it is defined somewhere as being equal to 03 (like an #include STATUS 03)(check the include files and/or your compiler settings)

Could you post the BTFSC description function ??

~RaGE();

Skins

Rage19-Jul-02 1:42

Rage

19-Jul-02 1:42

Hi !

Just like to know how difficult this is to skin a dialog app such winamp does (must be the 100000th to ask it, but ... Smile | :)

) ? Someone knows about a _good_ article on that ?

Thanks ...

~RaGE();

Re: Skins

James Spibey19-Jul-02 2:00

James Spibey

19-Jul-02 2:00

Yes, my article and it is VERY good.

http://www.codeproject.com/dialog/winampwnd.asp

I thank you

James

Re: Skins

Rage19-Jul-02 2:02

Rage

19-Jul-02 2:02

James Spibey wrote:
Yes, my article and it is VERY good.

Lol ... Ok, I´ll take it Smile | :)

James Spibey wrote:
http://www.codeproject.com/dialog/winampwnd.asp

well, i must really have searched like a '*Ä+ä#, because i did not find it on CP ...

Thanks a lot, that´s exactly what i was looking for.

~RaGE();

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