C / C++ / MFC

Nibu babu thomas27-Jan-08 21:18

Nibu babu thomas

27-Jan-08 21:18

Member 3100624 wrote:
my question is whether the XYZ object will be properly deleted thru the pvoid pointer WITHOUT typecasting? If the answer is no, then how does the 'free' delete using void pointers without knowing the amount of blocks that are to be freed?

Well the pointer will be deleted but not properly. The reason being that deleting a void pointer won't call that pointer's destructor function which will result in leaks if you have nested objects which in turn allocate memory.

Always pair "new" and "delete". Don't try to "new" and then use "free". "new" calls the constructor and "delete" calls the destructor. This allows all nested objects(which relies on the container class's destructor) to free themselves properly.

Nibu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http:\\nibuthomas.wordpress.com

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer27-Jan-08 22:22

27-Jan-08 22:22

Well answered. So well answered, that I tried to look at your blog. The link in your sig points to...

http://www.codeproject.com/script/Forums/%5C%5Cnibuthomas.wordpress.com[^]

Which you may want to change! I'm guessing changing /'s to \'s will help.

(And yes, I can edit the link I go to - may be that's a test to qualify for entry to your blog?)

Iain.

Nibu babu thomas27-Jan-08 23:44

Nibu babu thomas

27-Jan-08 23:44

Iain Clarke wrote:
Which you may want to change! I'm guessing changing /'s to \'s will help.

Worked for me, but anyway changed as you said, thanks! Smile | :)

Nibu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer28-Jan-08 0:05

28-Jan-08 0:05

It's better now. Maybe it's a firefox thing? IExplore was being friendler about the /\'s?

Iain.

Doubt!!!!

rowdy_vc++27-Jan-08 19:17

rowdy_vc++

27-Jan-08 19:17

Hi All..Thanks for your replay..

i have the total file length like this only .i wanna create the serial no this total length of the file how its possible ..

Lfile.Write("",Lfile.GetLength());

Lfile is nothing but object of CFile.This Lfile contains some list of datas.

Thanks!!

raju.k

Hamid_RT27-Jan-08 20:50

Hamid_RT

27-Jan-08 20:50

Do you want serial for files like (1) (2),...?

rowdy_vc++27-Jan-08 22:17

rowdy_vc++

27-Jan-08 22:17

hi hamid...thanks for ur replay

like this only..

1.
2.
3.
4.
etc

Thanks

raju.k

vijay_aroli27-Jan-08 22:31

vijay_aroli

27-Jan-08 22:31

Why have you created a new thread for asking something that you have asked in one of your earlier posts? There are some people trying to help you there and so I advice you to be patient and wait for someone to answer your question.

Don't expect that making a repost of the your questions by creating a new thread will get you answers quickly. If people have not been able to help you in the original thread, then its unlikely that they will answer here.

And seriously, though you have asked the question twice, i am still not able to figure out what you exactly want.

Regards,
Vijay.

Maxwell Chen27-Jan-08 22:36

27-Jan-08 22:36

vijay7173 wrote:
And seriously, though you have asked the question twice, i am still not able to figure out what you exactly want.

Me too!

Maxwell Chen

vijay_aroli27-Jan-08 22:51

vijay_aroli

27-Jan-08 22:51

Maxwell Chen wrote:
Me too!

well, I read your replies to the original post and I should say that you tried your best to help him. Smile | :)

Regards,
Vijay.

rowdy_vc++27-Jan-08 23:21

rowdy_vc++

27-Jan-08 23:21

hi vijay and all ..i read ur replay and i understood ..in feature i follow surely..i am new in this filed like VC++ ,code project also...

my question is ..

how to create serial no in a file ?
the output of file like this only..

1.
2.
3.

Thanks

raju.k

Drag image on to the explorer

David Crow28-Jan-08 6:21

David Crow

28-Jan-08 6:21

raju.k wrote:
how to create serial no in a file ?

Several ways exist. One such way is:

FILE *pFile = fopen(..., "w");
fprintf(pFile,  "1.\n");
fprintf(pFile,  "%d.\n", 2);
int x = 3;
fprintf(pFile,  "%d.\n", x);
fclose(pFile);

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

revanth198527-Jan-08 19:07

revanth1985

27-Jan-08 19:07

Hi,
I have a treecontrol containing files and folders as it items.Now i have added drag and drop support to and from explorer to my tree control.Everything is working fine but,when i drag a item from tree control i have created a drag image and assigned it to a pointer variable of CImageList class and using it i have dragged the image during drag.It works well inside the view but whrn the cursor leaves the the view it is getting struct at the border of the view.How can i move the image on to the explorer.I have registered my view as a droptarget.

Thanks

Re: Drag image on to the explorer

Hamid_RT27-Jan-08 20:49

Hamid_RT

27-Jan-08 20:49

I think codeproject has an example about drag to Explorer did you see it?

Re: Drag image on to the explorer [modified]

revanth198527-Jan-08 23:52

revanth1985

27-Jan-08 23:52

I am able to drag but image is getting struck at the end of the view.I have reffered Micheal dunn's example.

Thanks

modified on Monday, January 28, 2008 7:14:26 AM

Uncaught exception

George_George27-Jan-08 19:01

27-Jan-08 19:01

Hello everyone,

Just want to check whether my understanding is correct,

Both (1) and (2) only covers Windows C++ platform.

1. If there is uncaught exception, destructor is not ensured to be called for active object;

2. All the resources (handles, memory, etc.) for current process will be released when uncaught exception causing process to terminate.

thanks in advance,
George

Maxwell Chen27-Jan-08 19:31

27-Jan-08 19:31

For this kind of questions, you can test by yourself with DebugView tool.

Maxwell Chen

George_George27-Jan-08 19:41

27-Jan-08 19:41

Hi Maxwell,

I have used this tool before, but I do not think it has capability to monitor whether there is resource leak and whether destructor is called or not.

Maybe my knowledge about this tool is limited, and it is appreciated if you could help to give more information.

regards,
George

Maxwell Chen27-Jan-08 20:58

27-Jan-08 20:58

George_George wrote:
capability to monitor whether there is resource leak

DebugView can. And no special setting is required.

George_George wrote:
whether destructor is called or not.

You are the coder. You should trace this by yourself.

Maxwell Chen

George_George27-Jan-08 21:07

27-Jan-08 21:07

Hi Maxwell,

I have tried to use DebugView to find whether there is memory leak and leaked memory is released finally when process terminates, but there is no output in DebugView. Anything wrong?

int main()
{
	char* p = new char [100];

	p [0] = 'a';
	p [100] = 'z';
	return 0;
}

regards,
George

Maxwell Chen27-Jan-08 21:15

27-Jan-08 21:15

You have to add the detection utility in your code.

#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <ctrdbg.h>
void main()
{
  int* p = new int;
  _CrtDumpMemoryLeaks();
} // End.

Then DebugView display something when you execute the output program.

Maxwell Chen

George_George27-Jan-08 21:26

27-Jan-08 21:26

Thanks Maxwell,

I have tested your code and it works!

But I think it has limitation that it could only detect memory leak. How to detect others, like handles and locks? If DebugView could automatically monitor such resources, it will be great!

regards,
George

Maxwell Chen27-Jan-08 21:46

27-Jan-08 21:46

George_George wrote:
How to detect others, like handles and locks?

There is a Add-In for VC++ called the "Deleaker" for what you want.

Maxwell Chen

George_George27-Jan-08 22:01

27-Jan-08 22:01

Looks like not free and not Microsoft product?

http://www.deleaker.com/[^]

regards,
George

Maxwell Chen27-Jan-08 22:04