C / C++ / MFC

Re: vc++ + model dialog box

5-Mar-07 1:05

Refer, Life Cycle of a Dialog Box[^].

Prasad
Notifier using ATL | Operator new[],delete[][^]

Joan M5-Mar-07 1:41

Joan M

5-Mar-07 1:41

A dialog is the object that comes from a class, so you have a variable that must be instantiated.

In a modeless dialog, you can use, for example, a pointer to that class, and then reserve memory for that variable using the new clause. Once this has been done you can use CreateDialog in order to create that dialog and once this is done, you can use showwindow...

if it is modal, it's far easier, you have that variable (e.g: CDialog Dlg;) and then you have only to call DoModal();

But I think that the best you can do is to document yourself a little bit more. It is very important to get the basics very clear before trying to go further.

Hope this helps.

plot Library?

$uresh $hanmugam4-Mar-07 23:45

$uresh $hanmugam

4-Mar-07 23:45

Hi all

I need to plot values on a graph. Say for example I have an two integer vector

4,2,3,5,6,7
0.564,0.656,1.6456;

now i want to plot these values. What's the best way to do that?

I saw a Plot Graphic Library on this webpage "http://www.codeproject.com/miscctrl/pgllib.asp" but it not work with in VS2005, it will give some error.

error C2923: 'std::list' : 'std::vector<hull::tlineapproximator<t>::SPoint>::const_iterator' is not a valid template type argument for parameter '_Ty'

at

typedef std::vector<spoint> PointContainer;
//! Key containers
typedef std::list<pointcontainer::const_iterator> KeyContainer;

Can anyone help me what's wrong with "pgllib".
Thanks in advance

Re: plot Library?

prasad_som5-Mar-07 0:06

To get the space in pendrive

5-Mar-07 0:06

Why you are spamming[^] the forum ? Can't you be little patience?

Prasad
Notifier using ATL | Operator new[],delete[][^]

Vjys4-Mar-07 23:41

Vjys

4-Mar-07 23:41

Hai.
I am developing a VC++ app for a pendrive..
I want to know the available freespace in the drive..
Are there any APIs which i can use in my app to get the available free space in the drive..Iam not having any driver installed.
Waiting for suggestions..

Thanks in advance

Regards
vijay

Michael Dunn5-Mar-07 12:40

Michael Dunn

5-Mar-07 12:40

Check out GetDiskFreeSpaceEx()

--Mike--
Visual C++ MVP Cool | :cool:

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Ford, what's this fish doing in my ear?

Vjys5-Mar-07 19:16

Vjys

5-Mar-07 19:16

Thanks for your suggestion.
But in the parameters of the function, the directory name has to be given, but here iam having only handle of the device.Will it be ok with it or any other suggestions..

Here iam not having any driver installed..

Regards
vijay

Michael Dunn5-Mar-07 21:06

Michael Dunn

5-Mar-07 21:06

If there is no driver for the drive, how do you plan on accessing the drive at all?

--Mike--
Visual C++ MVP Cool | :cool:

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Ford, what's this fish doing in my ear?

Array of objects without default constructor gives runtime error

Vjys6-Mar-07 2:43

Vjys

6-Mar-07 2:43

Still now i am able to get the device descriptions without the help of driver and i want to proceed further. I got the handle to the device.
Can we do anything with the handle to get the solution.
Anyway the driver is going to do evrything with the help of handle only na..

Regards
vijay

sawerr4-Mar-07 23:38

sawerr

4-Mar-07 23:38

Hi I want to make array of objects without default constructor

#include <iostream><br />
<br />
using namespace std;<br />
<br />
class one <br />
{<br />
	int t;<br />
public: <br />
	one(int x):t(x) { cout << "Ctor" << endl;};<br />
     <br />
};<br />
<br />
int main(void) {<br />
one* o[8];<br />
for ( int i = 0; i < 8 ; i++)<br />
{<br />
	o[i] = new one(3);<br />
}<br />
delete[] o;<br />
}

I tired this. But it gives me run-time error with Vs 2005.
What is the problem?
Thanks

Re: Array of objects without default constructor gives runtime error

BadKarma4-Mar-07 23:50

BadKarma

4-Mar-07 23:50

Hi,

instead of deleting the array

delete[] o;

which you can't or at least shouldn't because its not allocated (hence it isn't on the heap but on the stack).
You need to delete the allocated one objects one by one

for ( int i = 0; i < 8 ; i++)
{
delete o[i];
}

codito ergo sum

Re: Array of objects without default constructor gives runtime error

sawerr5-Mar-07 0:12

sawerr

5-Mar-07 0:12

Hmm ok
Thank you

Re: Array of objects without default constructor gives runtime error

prasad_som5-Mar-07 0:11

DebugHeap --> memory overwritten[modified]

5-Mar-07 0:11

sawerr wrote:
one* o[8];

As told already, this is array of pointer to one. And Created on stack, so you dont need to worry about its memory.
And you need to free pointer memory for each index , which is allocated on heap.

Prasad
Notifier using ATL | Operator new[],delete[][^]

baerten4-Mar-07 23:24

baerten

4-Mar-07 23:24

Hi there

Since a sereval time i have very often strange problems with local variables.

char xxx[10] will cause an DebugHeapError by destruction ( if the function terminates )
a char *xxx = (char*)malloc(sizeof(char)*10); with a free(xxx); resolves the problem

a special DBF-Type (Date4) causes the same error.
The parameter pb from the function-calling static int __cdecl checkBytes(unsigned char * pb, ...
is unreadable (which causes the error)

Why are this kind of errors produces ( and why not since the begeinning of the project )

Big thanks

-- modified at 6:08 Monday 5th March, 2007

i debug the function which causes the error, now i see that the Date4 Pointer ( i changed the locale Date4 into a Date4*) will be overwritten with data at the initialisation of a char sss[10];

Why does the memory will be overwritten? WTF | :WTF:

Cedric Moonen5-Mar-07 0:43

Cedric Moonen

5-Mar-07 0:43

baerten wrote:
Why does the memory will be overwritten?

Because you are probably somewhere writing out of the bounds of an array. This will also give you the heap error.

Cédric Moonen
Software developer

Charting control [v1.1]

baerten5-Mar-07 1:19

baerten

5-Mar-07 1:19

After checking 2500 lines of code ...

it was indeed a corrupt char-array which provokes the overflow D'Oh! | :doh:

Thanks for your help

it's funny or more sadly, that a stupid error like this one happens at the first time of coding and
now after x years LOOOL C# with his strings makes the life too easy Laugh | :laugh:

Cedric Moonen5-Mar-07 3:09

Cedric Moonen

5-Mar-07 3:09

baerten wrote:
C# with his strings makes the life too easy

Just use a std::string in C++, that also make life easier Roll eyes | :rolleyes:

Cédric Moonen
Software developer

Charting control [v1.1]

prasad_som5-Mar-07 1:07