C / C++ / MFC Discussion Boards

OrangeV23-Jun-09 3:50

23-Jun-09 3:50

I'm not a C++ programmer, but I have some work to do with fixing a Memory Leak. I created a reference to an object called myObject:

myObject = CreateObject();

right?
So if I recreate that myObject by using:

myObject = CreateObject();

Again and it creates a new object will it overwrite that memory space and destroy the old object or do I have to delete myObject first and then write to that reference again?

Thanks for your help, I've been looking everywhere for this.

Re: Memory Leak Help

«_Superman_»23-Jun-09 4:02

«_Superman_»

23-Jun-09 4:02

You have to delete the previously created object before creating a new object.
If you have used new or new[] inside CreateObject you have to call delete or delete[] respectively.
If malloc is used, you have to call free.
If it is a COM object, you have to call its Release method.

«_Superman_»
I love work. It gives me something to do between weekends.

Re: Memory Leak Help

Stuart Dootson23-Jun-09 4:20

Stuart Dootson

23-Jun-09 4:20

It all depends on what CreateObject actually does...

If it does something like this:

struct Object
{
   whatever
};

Object CreateObject() { return Object(); }

then you don't need to do anything to myObject before reassigning to it.

If it uses a resource allocating function (e.g. new and malloc allocate memory, CreateFile, CreateEvent and CreateProcess allocate kernel handles, there are many more different examples of resource allocators) and passes control of that resource back to you, then you are responsible for deallocating that resource.

To show a simple example:

Object* CreateObject() { return new Object(); }

To reassign to myObject, you'd need to deallocate the thing referenced by myObject using delete myObject

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Memory Leak Help

Maximilien23-Jun-09 4:31

Maximilien

23-Jun-09 4:31

just to clarify :

does CreateObject() return a pointer to an object or a reference ?

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Re: Memory Leak Help

OrangeV23-Jun-09 4:44

OrangeV

23-Jun-09 4:44

It's just simply:

{return new Object();}

Re: Memory Leak Help

Stuart Dootson23-Jun-09 5:31

Stuart Dootson

23-Jun-09 5:31

In which case a delete myObject; is required to deallocate the object before assigning a different value to myObject - so long as the reference held by myObject hasn't been copied to some other variable.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Memory Leak Help

Pavan_Putra25-Jun-09 20:00

Pavan_Putra

25-Jun-09 20:00

No ,this will not overwrite the Memory Space.
if you have created object and collected the Reference it's just a reference (i.e. constant pointer).If you will assign it a new address it 'll not delete old object.(As it should not, Bcoz that object may be used ant where else).So if you are sure it is not usable now.Then call delete on it first .Then create new and assign value to it.

But if you are not assigning new value , set it to null ('ll save from Dangling pointer).

So you can say

if( myObject != NULL)
delete myObject;

myObject = CreateObject(); //or myObject = NULL;

It's not enough to be the best, when you have capability to be great....

Unicode again

bhanu_850923-Jun-09 3:39

bhanu_8509

23-Jun-09 3:39

Dear All,

I want to display Unicode characters in my CEdit control but it is not displaying and it is displaying as boxes. Any ideas ?

Bhanu

Re: Unicode again

Code-o-mat23-Jun-09 4:04

Code-o-mat

23-Jun-09 4:04

Is your project set to build for unicode?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

ShellExecute restriction?

rp_suman23-Jun-09 3:07

rp_suman

23-Jun-09 3:07

I am using the ShellExecute API to launch default E-mail client like "emailto:Email Ids". It is working well but when the number of characters exceed 1852, its not launching the E-mail client. The API is still returning success code only. My default mail client is Mozilla thunderbird. Is this a restriction in the API or any chance for E-mail client?

Thanks

--
"Programming is an art that fights back!"

Re: ShellExecute restriction?

Rajesh R Subramanian23-Jun-09 3:11

Rajesh R Subramanian

23-Jun-09 3:11

rp_suman wrote:
number of characters exceed 1852, its

Number of characters of what? Confused | :confused:

It is a crappy thing, but it's life -^ Carlo Pallini

Re: ShellExecute restriction?

Roger Stoltz23-Jun-09 3:16

Roger Stoltz

23-Jun-09 3:16

Are you by any chance running Win2k or earlier?
This article[^] may be of interest. The resulting command line may exceed 2047 chars.

However, I personally find an email address that exceeds 1852 chars to be rather uncommon. Suspicious | :suss:

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Re: ShellExecute restriction?

rp_suman23-Jun-09 3:30

rp_suman

23-Jun-09 3:30

The field can have more than one E-mail, so it may exceed 1852 occasionally. I checked same thing in system with outlook/Win XP the max limit was 1863.

--
"Programming is an art that fights back!"

Re: ShellExecute restriction?

Rajesh R Subramanian24-Jun-09 20:35

Rajesh R Subramanian

24-Jun-09 20:35

Roger Stoltz wrote:
However, I personally find an email address that exceeds 1852 chars to be rather uncommon.

Should be rather OK as long as you don't have to spell your email ID out to someone over the phone. Laugh | :laugh:

It is a crappy thing, but it's life -^ Carlo Pallini

Re: ShellExecute restriction?

Rajesh R Subramanian23-Jun-09 3:30

Rajesh R Subramanian

23-Jun-09 3:30

I'm assuming that you are clubbing too many email ids separated by semicolons? I tried by increasing the no. of email ids with every trial. At some point, ShellExecute started returning a value NOT greater than 32 (it returns a value greater than 32 if it succeeds) and the return value was, upon failure, SE_ERR_ACCESSDENIED.

You might want to check the return value properly.

It is a crappy thing, but it's life -^ Carlo Pallini

Re: ShellExecute restriction?

Rozis23-Jun-09 6:12

Rozis

23-Jun-09 6:12

I think it has to do with the lenght of the commandline. What you could do is put your line in a batchfile (just generate the file from within your program) and run that one. Just delete it when ready..

Rozis

Need help on how to send SMS using VC++ program

John50223-Jun-09 1:30

John502

23-Jun-09 1:30

Hi,
I need help on how to send SMS using VC++ program to my mobile.., This is my requirement, Can any one help me out regarding this..?

Thanks in advance..

Re: Need help on how to send SMS using VC++ program

Hamid_RT23-Jun-09 1:50

Hamid_RT

23-Jun-09 1:50

See
Sending an SMS using CEMAPI[^]
SMS and Pager Toolkit[^]
Short Message Service (SMS) API[^].

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

how to get handle to a window

B060611523-Jun-09 1:11

B0606115

23-Jun-09 1:11

hi!
i want to use handle to a window in one of my function but do not know how to get handle to a window kindly help me.
thanx in advance

Re: how to get handle to a window

Roger Stoltz23-Jun-09 1:22

Roger Stoltz

23-Jun-09 1:22

B0606115 wrote:
i want to use handle to a window in one of my function but do not know how to get handle to a window

Well, what do you have? A CWnd*? Nothing?
You could probably benefit from ::FindWindow()[^] or ::EnumWindows()[^].

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Re: how to get handle to a window

CPallini23-Jun-09 1:38

CPallini

23-Jun-09 1:38

What window? Is one of your application windows? Please provide details.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

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[My articles]

Re: how to get handle to a window

Luc Pattyn23-Jun-09 2:12

Luc Pattyn

23-Jun-09 2:12

what details do you want? the handle perhaps???

Smile | :)

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DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Re: how to get handle to a window

Roger Stoltz23-Jun-09 2:21

Roger Stoltz

23-Jun-09 2:21

Luc Pattyn wrote:
what details do you want? the handle perhaps???

Or he probably need a "handle" with that... Poke tongue | ;-P

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

Re: how to get handle to a window

CPallini23-Jun-09 2:28

CPallini

23-Jun-09 2:28

Roger Stoltz wrote:
Or he probably need a "handle" with that...

Exactly.

Re: how to get handle to a window

Rajesh R Subramanian23-Jun-09 1:59

Rajesh R Subramanian

23-Jun-09 1:59

You approach the window gently, and say: "Hi Window, may I please have your handle? Thanks!".

Seriously though, you need to provide more information than that to get an answer that can be of use. Smile | :)

It is a crappy thing, but it's life -^ Carlo Pallini

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