Re: CArray memory issue - C / C++ / MFC Discussion Boards

Nishad S16-May-06 18:54

16-May-06 18:54

I think that is a last resort... !
As this control is supposed to be a common, I need to avoid such dependencies.

- NS -

Re: Key stroke watching

Nibu babu thomas16-May-06 18:59

Nibu babu thomas

16-May-06 18:59

NS17 wrote:
I think that is a last resort... !
As this control is supposed to be a common, I need to avoid such dependencies.

Well that is how keyboard messages are set to function. If a control is to receive input from keyboard it should have the Input Focus. This the rule. You cannot break that. Smile | :)

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: Key stroke watching

Nishad S16-May-06 19:06

Nishad S

16-May-06 19:06

mmm....
So now I am planning to expose a function to allow the app to call in its PreTranslateMessage, like the RelayEvent() of ToolTip Ctrl. What's your opinion?

- NS -

Re: Key stroke watching

Nibu babu thomas16-May-06 19:17

Nibu babu thomas

16-May-06 19:17

NS17 wrote:
So now I am planning to expose a function to allow the app to call in its PreTranslateMessage, like the RelayEvent() of ToolTip Ctrl. What's your opinion?

Well if you want such functionality that's an option. You can also take look at the FORWARD_WM_********* group of macros which could also help you.

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: Key stroke watching

Nishad S16-May-06 19:21

Nishad S

16-May-06 19:21

Ok, thank you... Let me try Smile | :)

- NS -

CArray memory issue

mohanrajh16-May-06 18:15

mohanrajh

16-May-06 18:15

Hey guys,
I would like to know what happends with memory in this code,

CArray<int,int> myArray;

//my array could be 0 or can grow upto 1000
myArray.SetSize(0,1000);

for (int j = 0; j < 900; j++)
{
myArray.Add(j);
}

//what is below line going to do?
myArray.FreeExtra();

Is SetSize & FreeExtra functions anyway improves anything here or it would be better of without these lines.
Thanks

Mohan

Re: CArray memory issue

Christian Graus16-May-06 18:24

Christian Graus

16-May-06 18:24

http://www.google.com.au/search?hl=en&q=CArray+FreeExtra&meta=[^]

FreeExtra apparrenty will free any memory allocated, but I would guess what it does depends on the classes grow policy, no memory was pre allocated.

std::vector is a far better container to use than CArray.

Christian Graus - Microsoft MVP - C++

Re: CArray memory issue

NiceNaidu16-May-06 18:36

NiceNaidu

16-May-06 18:36

CArray<CPoint,CPoint> myArray;<br />
int i;<br />
<br />
// Allocate memory for at least 32 elements.<br />
myArray.SetSize(32, 128);<br />
<br />
// Add elements to the array.<br />
CPoint* pPt = (CPoint*) myArray.GetData();<br />
for (i=0;i < 32;i++,pPt++)<br />
   *pPt = CPoint(i, 2*i);<br />
<br />
// Only keep first 5 elements and free extra (unused) bytes.<br />
myArray.SetSize(5, 128);<br />
myArray.FreeExtra();

Look at the above code .

Hope now u can understand the use of FreeExtra.

Appu..
"If you judge people, you have no time to love them."

Re: CArray memory issue

Laxman Auti16-May-06 18:29

Laxman Auti

16-May-06 18:29

HI Mohan,
function FreeExtra():

Frees any extra memory that was allocated while the array was grown. This function has no effect on the size or upper bound of the array

function SetSize():

Use this function to set the size of your array before you begin using the array. If you do not use SetSize, adding elements to your array causes it to be frequently reallocated and copied. Frequent reallocation and copying are inefficient and can fragment memory

...referenced from MSDN oct 2001

Knock out 'T' from CAN'T ,
You 'CAN' if you think you 'CAN'
Cool | :cool:

Re: CArray memory issue

grigsoft16-May-06 19:08

grigsoft

16-May-06 19:08

With SetSize your code runs faster - memory for 1000 items is allocated and not copied\extended during adding new items. Without it array will allocate new memory several times, copying all items to new location.
FreeExtra just free unused memory - but it have to copy whole array to new location, which cost time. So I almost never use it - if you will want to add new item afterwards, you will cause array to copy items again.

Igor Green
http://www.grigsoft.com/ - files and folders comparison tools

Re: CArray memory issue

mohanrajh17-May-06 15:08

mohanrajh

17-May-06 15:08

Igor,

I kinda got a clue, thanks. But i got a question...

I load the array only once when my application loads & then i just use it for reference purpose only, in this case if i include SetSize(0,1000) & the array loads only 500 items, will that mean the memory for other 500 still exists & not released?

Thanks.

Mohan

Re: CArray memory issue

grigsoft17-May-06 20:55

grigsoft

17-May-06 20:55

Yes, that's true.

Igor Green
http://www.grigsoft.com/ - files and folders comparison tools

string..

Prinz Ryoiji16-May-06 18:08

Prinz Ryoiji

16-May-06 18:08

can anyone teach me how to get string input and display it in the blackbox?

fe8her

Re: string..

Nibu babu thomas16-May-06 18:10

Nibu babu thomas

16-May-06 18:10

Prinz Ryoiji wrote:
it in the blackbox?

Is this a Console Application? Unsure | :~

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: string..

Prinz Ryoiji16-May-06 18:17

Prinz Ryoiji

16-May-06 18:17

yupe..
win32 console application..

Re: string..

Nibu babu thomas16-May-06 18:24

Nibu babu thomas

16-May-06 18:24

That blackbox is called console.

Well I wrote an example for you and then I lost the whole thing (Page cannot be displayed).

Well CG has done that for you...

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: string..

Prinz Ryoiji16-May-06 18:33

Prinz Ryoiji

16-May-06 18:33

owh..ok..

thanks...

Re: string..

Maxwell Chen16-May-06 18:35

Maxwell Chen

16-May-06 18:35

Nibu thomas wrote:
That blackbox is called console.

Also called "DOS-Box" in some books ...

Maxwell Chen

Re: string..

Prinz Ryoiji16-May-06 18:45

Prinz Ryoiji

16-May-06 18:45

owh..ok..

thanks a lot!

Re: string..

Nibu babu thomas16-May-06 18:57

Nibu babu thomas

16-May-06 18:57

You can change the black box to green box...

Just add this line of code

system("color 2f");//hehe

:->

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: string..

Maxwell Chen16-May-06 19:47

Maxwell Chen

16-May-06 19:47

Nibu thomas wrote:
change the black box to green box...

Maxwell Chen

Re: string..

Nibu babu thomas16-May-06 19:50

Nibu babu thomas

16-May-06 19:50

Maxwell Chen wrote:

Start->Run->Cmd

Enter following command...

Color 2f

The background color changes from black to green hence from black box to green box...:-> Roll eyes | :rolleyes:

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: string..

Maxwell Chen16-May-06 20:23

Maxwell Chen

16-May-06 20:23

Nibu thomas wrote:
Color 2f

Yeah, I know. I was trying to show you a green face. Roll eyes | :rolleyes:

Maxwell Chen

Re: string..

Nibu babu thomas16-May-06 20:24

Nibu babu thomas

16-May-06 20:24

Maxwell Chen wrote:
Yeah, I know. I was trying to show you a green face. ;P

Nibu thomas
Software Developer

Faqs by Michael dunn

Re: string..

Maxwell Chen16-May-06 20:34

Maxwell Chen

16-May-06 20:34

The readme says: The first nibble for the BK color, and the second nibble for the foreground color.

Value F = Bright White.

But when I issue color FF, it resets to system color! D'Oh! | :doh:

Maxwell Chen

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