Re: Question about dynamically allocated memory - C / C++ / MFC Discussion Boards

Question about dynamically allocated memory

Eikthrynir31-Aug-06 21:37

31-Aug-06 21:37

Hi!
I have a question about dynamically allocated memory, actually about cleaning that memory.
For example I compile and run this piece of code:

char *pString = NULL;
if ( (pString = new char [100]) == NULL )
  exit( EXIT_FAILURE );

... <--- Use pString

delete [] pString;

The question is how does the program know how much memory (how many bytes) to free (deallocate)? Isn't it compulsory to specify the number of bytes between the two brackets in order to be sure that it will free all the dynamically allocated memory? Confused | :confused:

Any suggestions would be greatly appreciated!
Thanks in advance!

Re: Question about dynamically allocated memory

Stephen Hewitt31-Aug-06 21:43

Stephen Hewitt

31-Aug-06 21:43

Each heap allocation keeps track of its size.

Steve

Re: Question about dynamically allocated memory

prasad_som31-Aug-06 22:21

prasad_som

31-Aug-06 22:21

See this[^]

Prasad
Notifier using ATL

Re: Question about dynamically allocated memory

Hamid_RT31-Aug-06 22:48

Hamid_RT

31-Aug-06 22:48

See here[^]

WhiteSky

Re: Question about dynamically allocated memory

Cedric Moonen31-Aug-06 23:02

Cedric Moonen

31-Aug-06 23:02

Did you read his question ??

The link you posted has nothing to do with new and delete, it is purely C programming (alloc, malloc, realloc, ...).
When posting a link, at least take the time to verify if it contains valuable information for the OP.

Just googling and pasting the first link that cames up is not really helpfull.

Cédric Moonen
Software developer

Charting control [Updated - v1.1]

Re: Question about dynamically allocated memory

Hamid_RT1-Sep-06 1:02

Hamid_RT

1-Sep-06 1:02

It seems I must read complete a thread not only title,thanks for remind,sometime when I see a title I guess body is like title (thanks), but i dont think that stuff and paste link is good,yes?

WhiteSky

Re: Question about dynamically allocated memory

Cedric Moonen1-Sep-06 1:14

Cedric Moonen

1-Sep-06 1:14

WhiteSky wrote:
It seems I must read complete a thread not only title

Of course !! That seems logical no ? How can you describe completely a problem in one single title line ??

WhiteSky wrote:
but i dont think that stuff and paste link is good

It depends. Sometimes it is usefull, but sometimes it can be really annoying. For example if that links to a lot of text and if the OP needs to search a lot to find the information, it is in general not very valuable. And if you provide a link to something you googled for, then at least verify that it contains the information.

We ask the people who post the questions to have some respect for the other (so formulate the questions correctly, use proper english if possible, ...) but the opposite is true also.

Cédric Moonen
Software developer

Charting control [Updated - v1.1]

Re: Question about dynamically allocated memory

Hamid_RT1-Sep-06 1:32

Hamid_RT

1-Sep-06 1:32

Cedric Moonen wrote:
Of course !! That seems logical no ? How can you describe completely a problem in one single title line ??

"How to show a bmp file on background of dialog"
a title i think see yesterday not sure well
anyway when you see this sentence what do you think?so its possible of course not always.
--------------------------
...but sometime Im wondering because you see a question and sender explain a lot of then you search and find a site when you answer to sender he say its very helpful,great and... but i want to know why sender doesnt search or sometime some one ask what is ?(it) without any try

WhiteSky

clrscr()

Rajesh R Subramanian31-Aug-06 21:22

Rajesh R Subramanian

31-Aug-06 21:22

I am on a console application that supports MFC. In turbo C under dos, we can use the clrscr(); command to clear the screen. Is there any equivalent which I can use in my case (console app that supports MFC)?

Thanks
Brahmma

You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.

Re: clrscr()

_AnsHUMAN_ 31-Aug-06 21:49

_AnsHUMAN_

31-Aug-06 21:49

brahmma wrote:
command to clear the screen

Try this:
system("cls");

I hope this helps...

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: clrscr()

toxcct31-Aug-06 22:20

toxcct

31-Aug-06 22:20

using system() is bad. windows provides an API for consoles, but i don't remember its name...

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: clrscr()

_AnsHUMAN_ 31-Aug-06 22:54

_AnsHUMAN_

31-Aug-06 22:54

Thanks for making me recall that. It was just a quick suggestion.
See Here for some information on Console's

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Greek in CEdit control

LeathurBoy31-Aug-06 20:48

LeathurBoy

31-Aug-06 20:48

I need to display Greek and English in two different CEdit controls on a dialog. How can I do this?

Re: Greek in CEdit control

ThatsAlok1-Sep-06 0:46

ThatsAlok

1-Sep-06 0:46

LeathurBoy wrote:
need to display Greek and English in two different CEdit controls on a dialog. How can I do this?

enable UNICODE in your program

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You

icon files!!

harsha_123431-Aug-06 20:34

harsha_1234

31-Aug-06 20:34

hi group!!

i have got one bmp file and i want to convert it to ico file
actually i want to create logo for application
so what is the way for it?
are there any readymade softwares!!
please help me Confused | :confused:

thanks and regards
harshal

Re: icon files!!

Programm3r31-Aug-06 20:37

Programm3r

31-Aug-06 20:37

Is this related to MFC or C++?? Confused | :confused:

Why not just opening it in MS paint, and saving it in a ico format??

OMG | :OMG:

Regards

Programm3r

Re: icon files!!

PJ Arends31-Aug-06 21:12

PJ Arends

31-Aug-06 21:12

Have a look at CreateIconIndirect(). In the ICONINFO structure specify your bitmap as the hbmColor bitmap and create a monochrome black bitmap with the same dimensions as your bitmap for the hbmMask bitmap.

You may be right
I may be crazy
-- Billy Joel --

Within you lies the power for good, use it!!!

Re: icon files!!

Hamid_RT31-Aug-06 22:16

Hamid_RT

31-Aug-06 22:16

See an example in msdn "IconPro" but im not sure it convert bmp to icon(its for extract icon form dll/exe)

WhiteSky

Re: icon files!!

MayankT1-Sep-06 1:10

MayankT

1-Sep-06 1:10

In MSPaint do a 'select all; copy'

then in VS do 'File->New->File...->Icon file'

then 'paste'

----------------------
Mayank Thakore
Learning C++ - since 1998

They didn't print my card right; so I resigned.

Registry Entries

Programm3r31-Aug-06 20:24

Programm3r

31-Aug-06 20:24

Hi all,

Does anyone know how to create a registry entry. Nothing to complex just a normal registry entry. So if anyone knows of a site or have a small piece of code ... Big Grin | :-D

Thanx in advance

Regards

Programm3r

Re: Registry Entries

Stephen Hewitt31-Aug-06 20:46

Stephen Hewitt

31-Aug-06 20:46

Using MFC? Straight Win32?

Here's an example using straight Win32 calls. As you can see using a wrapper class as provided by MFC of ATL (and no doubt many others) would make things a lot simpler.

--------------------

// Create or open the key.
HKEY hKey;
LONG res = RegCreateKeyEx(
HKEY_CURRENT_USER,
_T("Software\\My Company\\My Product"),
0,
NULL,
REG_OPTION_NON_VOLATILE,
KEY_ALL_ACCESS,
NULL,
&hKey,
NULL
);
if (res==ERROR_SUCCESS)
{
// Now write a value in the key we opened/created.
DWORD Value = 5; // Value to write to registry.
res = RegSetValueEx(
hKey,
_T("My value"),
0,
REG_DWORD,
reinterpret_cast<const BYTE*>(&Value),
sizeof(Value)
);

// Close the key.
RegCloseKey(hKey);
}

Steve

Re: Registry Entries

Programm3r31-Aug-06 20:47

Programm3r

31-Aug-06 20:47