C / C++ / MFC

toxcct29-Jul-08 6:15

29-Jul-08 6:15

__DanC__ wrote:
how would I free an array created like:

WCHAR pwszRealPath[MAX_PATH];

such an array is created on the stack, and not on the heap.
so basically, no need to free it Wink | ;)

it will be destroyed when going out of scope, of at program termination if static/global...

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__DanC__29-Jul-08 6:17

__DanC__

29-Jul-08 6:17

Thanks, that is what I thought would be the case but wanted to clarify in case I go causing any memory leaks!

toxcct29-Jul-08 6:33

29-Jul-08 6:33

to be very clear here is what happens with this code:

char* pArray = new char[123];

a variable pArray of type pointer to char is created on the stack.
then, a block of 123 chars is allocated on the heap.
the address of the just allocated memory is stored into the pointer variable you have on the stack (pArray).

so, if you put such a code into a scope, and if you don't free the memory allocated before going out of scope, the variable on the stack is destroyed, but not the memory block on the heap.
so you just loose the reference (the address) to your allocated memory on the heap, hence the memory leak...

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Cedric Moonen29-Jul-08 7:32

Cedric Moonen

29-Jul-08 7:32

To make things even more simple, there's only one little rule to remember:
everything that is allocated with new should be deleted using delete; everything that is allocated with new...[] should be deleted using delete[] and everything that is allocated with malloc should be deleted with free.
For the rest, you don't have to care (and Toxcct explained that a bit more in details).

Cédric Moonen
Software developer

Charting control [v1.4]
OpenGL game tutorial in C++

Joe Woodbury29-Jul-08 8:50

Joe Woodbury

29-Jul-08 8:50

But what about GlobalAlloc()?

(Sorry, couldn't resist. Smile | :)

)

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Yajnesh Narayan Behera29-Jul-08 19:10

Yajnesh Narayan Behera

29-Jul-08 19:10

There is a verry good discussion here
http://www.codeguru.com/forum/showthread.php?t=55854[^]

Joe Woodbury30-Jul-08 5:11

Joe Woodbury

30-Jul-08 5:11

I was making a joke.

Anyone who thinks he has a better idea of what's good for people than people do is a swine.
- P.J. O'Rourke

Ownerdrawn Listbox

KellyR29-Jul-08 4:23

KellyR

29-Jul-08 4:23

Hi, I'm looking for a way to do a completely owner-drawn Listbox in C++ with just the Windows API and without MFC. The LBS_OWNERDRAWFIXED allows me to draw the items in the list, but is there a way for me to owner-draw the entire listbox (along with the scroll bars, etc)? Or do I have to subclass the listbox and draw it when it receives WM_PAINT?

Thanks!

led mike29-Jul-08 4:36

led mike

29-Jul-08 4:36

Well owner draw does what it does. You can't make it do something it doesn't do. Does that answer your question?

led mike

KellyR29-Jul-08 4:38

KellyR

29-Jul-08 4:38

I was hoping there was a listbox ownerdraw style that would have the same behavior as BS_OWNERDRAW does for buttons. I guess you're saying there isn't one?

led mike29-Jul-08 5:10

led mike

29-Jul-08 5:10

KellyR wrote:
I guess you're saying there isn't one?

Yes. As far as I know there is only one owner draw mechanism for each control that supports owner draw.

led mike

KellyR29-Jul-08 5:30

KellyR

29-Jul-08 5:30

ok, thanks!

Executing Query like (where) expressions on data stored in structure in c++

Mark Salsbery29-Jul-08 6:32

Mark Salsbery

29-Jul-08 6:32

With a listview control, you could maybe take advantage of custom draw...

Customizing a Control's Appearance Using Custom Draw[^]

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

NileshBhatkhalkar29-Jul-08 4:12

NileshBhatkhalkar

29-Jul-08 4:12

Hi.

I have created a simple database table using class / structure in C++. For ex.
<pre>
class StudentTable{
int m_nRollNo;
CString m_strFirstName;
unsigned int m_uAge;
unsigned short m_uPercentageOfMarks;
};
</pre>
The records are stored in stl vector.

Now I want the execute query like expressions on the data for ex.
"m_uPercentageOfMarks >= 80 and m_strFirstName like 'A%'" - First name starting with A for matching is ok

How do I execute these query expressions with the stored data? Parsing the expression is ok but how to relate these fields + operator (and/or/not) and actually execute these expressions in one go..

Please suggest how this can be achieved.

Thanks in advance.

Thanks & Regards,
Nilesh Prakash Bhatkhalkar

Re: Executing Query like (where) expressions on data stored in structure in c++

led mike29-Jul-08 4:35

led mike

29-Jul-08 4:35

NileshBhatkhalkar wrote:
Please suggest how this can be achieved.

As far as I know nothing standard exists as one library that will do that for you, you would have to develop it yourself. That's why most people use databases or something else that meets their requirements.

led mike

Globalization/Localization in VC++ [modified]

Andy Rama29-Jul-08 3:31

Andy Rama

29-Jul-08 3:31

Hi to all,

How to do Globalization/Localization in VC++?

Regards,
Aniket A. Salunkhe

modified on Tuesday, July 29, 2008 11:44 AM

toxcct29-Jul-08 3:46

29-Jul-08 3:46

what do you mean by "Globalization" ?

have variables global ?
make "global" libraries ?

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Maximilien29-Jul-08 3:50

Maximilien

29-Jul-08 3:50

me think he's talking about localization.

Andy Rama29-Jul-08 5:47

Andy Rama

29-Jul-08 5:47

Maximilien wrote:
localization.

yes

toxcct29-Jul-08 5:59

29-Jul-08 5:59

so what part of localization do you want to know about ?

making the application multilingual for instance ?
or much complex ones ?

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modified on Tuesday, July 29, 2008 1:35 PM