C / C++ / MFC

Re: using delete operator- part II

13-Jun-06 1:48

hi Cedric,
Can you just brief me on what problem would be there if I use delete[] to delete a single object?
I just read that using the delete[] method is the best way to delete an object as it deletes the memory associated with the array or the object completely

Thanks anyways I got the answer in Viorel's post
Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

-- modified at 7:50 Tuesday 13th June, 2006

Cedric Moonen13-Jun-06 2:05

Cedric Moonen

13-Jun-06 2:05

Because delete[] expects the number of items in your array to be just before the address of the first element. This value is not present when you use new. Thus, you will have some problems because you first try to read the number of items where you shouldn't.

Cédric Moonen
Software developer

Charting control

Re: using delete operator- part II

David Crow13-Jun-06 3:51

David Crow

13-Jun-06 3:51

_AnShUmAn_ wrote:
delete x ; //works for a single object
delete[] x; // deletes the complete array

He's already indicated he knows the difference. Read his original question again. Roll eyes | :rolleyes:

"The largest fire starts but with the smallest spark." - David Crow

"Judge not by the eye but by the heart." - Native American Proverb

Re: using delete operator- part II

_AnsHUMAN_ 13-Jun-06 3:59

Re: using delete operator

13-Jun-06 3:59

and you guess what,
you didn't follow what the rest of the posts were for ?

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

_AnShUmAn_

Viorel.13-Jun-06 1:48

Viorel.

13-Jun-06 1:48

When delete [] is called, the system organizes a loop according to the number of allocated items. Within this loop, the system calls the destructor, if any. The number of iterations is got from internal values made by new operator.

We cannot rely on the idea that the new operator, used in non-array manner, stores all of internal values needed by delete []. It depends on implementations. For instance, in my tests (VS 2003), the delete [] statement fails if is executed for a single object allocated with new, and that object has a virtual destructor.

In case of objects with no destructor, like BYTE, the system does not need to known the number of iterations, therefore the delete [] acts like delete.

I think delete [] must be only used with arrays. Even if in some implementations the internal information allows using of delete [] for non-array objects, where delete is expected, it will be slower, because of the loop actually executed a single time.

embed multiple child dialogs on main dialog

Raghunandan S13-Jun-06 1:02

Raghunandan S

13-Jun-06 1:02

Hi All,
I need to design a dialog box which has 2 sections. the left section is a tree control and right section displays various controls.Based on the user's selection in the tree control, I need to display different controls(like property pages...)in the right section.I have created separate dialogs for each of the selections and I need to embed this template onto the main dialog upon user's selection.Please let me know how to achieve this.

Thanks in advance
Raghu

Laxman Auti13-Jun-06 1:07

Laxman Auti

13-Jun-06 1:07

Raghunandan wrote:
need to design a dialog box which has 2 sections. the left section is a tree control and right section displays various controls.Based on the user's selection in the tree control, I need to display different controls(like property pages...)in the right section.I have created separate dialogs for each of the selections and I need to embed this template onto the main dialog upon user's selection.Please let me know how to achieve this.

Make the other dialogs as child and use the following code to create the dialogs in main Dialog.

CDialog *dlg=new CDialog()<br />
dlg->Create(Dialog ID);<br />
dlg->ShowWindow(SW_SHOW);

Use MoveWindow to set the dialog at appropriate position. or set the dialog co-ordinates.

Knock out 't' from can't,
You can if you think you can
Cool | :cool:

_AnsHUMAN_ 13-Jun-06 1:09

13-Jun-06 1:09

You can use SetWindowPos and put the dialogs in modeless form.

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

_AnShUmAn_

Ganesh_T13-Jun-06 1:12

Ganesh_T

13-Jun-06 1:12

Set the Style property of Dialogs as child .

Now do as follows in your implementation file :

CDialog *dlg= new CChildDialog();
dlg->SetWindowPos(...);
dlg->ShowWindow(SW_SHOW);

Cheers
"Peace of mind through Technology"

Raghunandan S13-Jun-06 1:17

Raghunandan S

13-Jun-06 1:17

the problem with these solutions are that the child dialog get closed upon pressing escape or enter when the focus in any of the controls

Raghu

Hamid_RT13-Jun-06 1:45

Hamid_RT

13-Jun-06 1:45

See Here[^] maybe it is some helpful to you
you need to override OnOk and OnCancel

whitesky

XML Parsing [modified]

XalanXalan13-Jun-06 0:54

13-Jun-06 0:54

I have an xml ABC.xml of the following structure.
(ROOT)
(Group value="GRA0")
(Option value="OPA1"/)
(Option value="OPA2"/)
(Option value="OPA3"/)
(/Group)
(Group value="GRA1")
(Option value="OPA4"/)
(Option value="OPA5"/)
(Option value="OPA6"/)
(/Group)
(Group value="GRA2")
(Option value="OPA7"/)
(Option value="OPA8"/)
(Option value="OPA9"/)
(/Group)
(/ROOT)

I need to parse this xml and get all the values of nodes. I shall be grateful if i get the code in VC++.

-- modified at 7:04 Tuesday 13th June, 2006

_AnsHUMAN_ 13-Jun-06 0:55

13-Jun-06 0:55

where is the structure?

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

_AnShUmAn_

XalanXalan13-Jun-06 0:57

13-Jun-06 0:57

<root>
<gp value="GPA0">
<op value="OP1">
<op value="OP2">
<op value="OP3">

<gp value="GPA1">
<op value="OP4">
<op value="OP5">
<op value="OP6">

<gp value="GPA2">
<op value="OP7">
<op value="OP8">
<op value="OP9">

</

XalanXalan13-Jun-06 0:58

13-Jun-06 0:58

something is wrong. the xml is not showing up.

_AnsHUMAN_ 13-Jun-06 0:59

13-Jun-06 0:59

Try putting in the "pre" blocks or the "code" blocks

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

_AnShUmAn_

Viorel.13-Jun-06 1:03

Viorel.

13-Jun-06 1:03

Try Ignore HTML tags in this message (good for code snippets) option when you post the XML sample.

Ganesh_T13-Jun-06 0:58

Ganesh_T

13-Jun-06 0:58

Can any one parse the InVisible structure....

Cheers
"Peace of mind through Technology"

XalanXalan13-Jun-06 1:05

13-Jun-06 1:05

(ROOT)
(Group value="GRA0")
(Option value="OPA1"/)
(Option value="OPA2"/)
(Option value="OPA3"/)
(/Group)
(Group value="GRA1")
(Option value="OPA4"/)
(Option value="OPA5"/)
(Option value="OPA6"/)
(/Group)
(Group value="GRA2")
(Option value="OPA7"/)
(Option value="OPA8"/)
(Option value="OPA9"/)
(/Group)
(/ROOT)