Code Writing - C / C++ / MFC Discussion Boards

MeterMan21-Mar-04 13:30

21-Mar-04 13:30

Just curious all the tutorials i have came upon doesn't address this issue. How do you append to a file using serialization? I have a database (text file) dialog program i made that will write to a file and read from the file. However it overwrites preexisting data. Help on this would be great. I know fsopen has +a is there anything like that in serialization?

Win32newb
"Making windows programs worse than they already are"

Re: Where is modeAppend in Serialization?

Rob Manderson21-Mar-04 21:52

Rob Manderson

21-Mar-04 21:52

Appending with serialisation makes no sense. The point of serialisation is that you have a data structure somewhere in memory that you want to save to disk and read back sometime later. The serialisation process doesn't just save the data, it saves metadata to make it possible to read both the data and the data structure back later. Deserialisation recreates your datastructure (with all the pointers from high level objects to lower level objects intact). Thus, the only way that appending makes sense is to 'append' an object of some kind to the original structure in memory. Appending data to a 'file' that contains serialisation data without reference to the original data will result in 'orphaned' objects existing in your memory - objects you can't reference because your original data structure has no idea they exist.

Rob Manderson

Colin Davies wrote: I'm sure Americans could use more of it, and thus reduce the world supply faster. This of course would be good, because the faster we run out globally, the less chance of pollution there will be. (Talking about the price of petrol) The Soapbox, March 5 2004

CDialogBar does not support controls

krugger21-Mar-04 13:19

krugger

21-Mar-04 13:19

HI all;

I am building an application which should have a tab control on a CDialogBar. Visual C++ gladly added the dockable dialog bar for me but i could not figure out where to put the code to create the tab control since the OnInitDialog() function is simply ineffective. Can anybody please help out. I need to know where i should place my code to create the TAb control on the dialogbar.

I badly need this guys;

THanks

Krugger

Re: CDialogBar does not support controls

Rob Manderson21-Mar-04 22:04

Rob Manderson

21-Mar-04 22:04

Let's assume you're trying to create the object using DDX. In other words, you've embedded an object of the correct type in your class definition and written a DoDataExchange function with the appropriate DDX_Control() call.

It might look like this (simplified).

Header file.

C++

class CMyDialogBar : public CDialogBar
{
public:
    CMyTabbedControl  m_tabControl;

    virtual void DoDataExchange(CDataExchange* pDX);
    virtual void OnInitDialog();
};

and your implementation file looks like this.

C++

void CMyDialogBar::DoDataExchange(CDataExchange* pDX)
{
    CDialogBar::DoDataExchange(pDX);
    DDX_Control(pDX, IDC_MYTABCONTROL, m_tabControl);
}

void CMyDialogBar::OnInitDialog()
{
    CDialogBar::OnInitDialog();

    return TRUE;
}

And yet it doesn't work. As you've noticed, OnInitDialog() isn't called for a DialogBar. The solution I found was to add a function Initialise() to the DialogBar derived class and call it once I knew the dialog bar had been created.

C++

void CMyDialogBar::Initialise()
{
    UpdateData(FALSE);
}

Yes, it's that simple. Just call UpdateData() (make sure the call occurs before any code that tries to use the TabControl) and the control will be created.

Rob Manderson

Colin Davies wrote: I'm sure Americans could use more of it, and thus reduce the world supply faster. This of course would be good, because the faster we run out globally, the less chance of pollution there will be. (Talking about the price of petrol) The Soapbox, March 5 2004

How to develop a printing server?

alongal21-Mar-04 10:28

alongal

21-Mar-04 10:28

Hi,

I have scanner program that send scanned pictures to printer through firewire.
I want to develop a server in Visual C++ that will recieve the scanned pictures instead of the printer, will schedule them, and send them to the printer.
Both connections of scanner->server and server->printer should be by firewire (The speed is the most important issue for me).

Any one has an idea how to cope with this issue?
Should the server pretend to be a printer, so the scanner will send the pictures to it?
Do I have to dig into the printing protocol in order to enable the server communicate with both scanner and printer?
I don't have a clue how to approch this issue Confused | :confused:

,
So any help will be very appreciated.

Thanks,
Alon

edit control

ami121-Mar-04 8:55

ami1

21-Mar-04 8:55

hi
how can i scroll to the end of an edit control each time I add text.i am not using mfc only the windows api functions.
thanks

Re: edit control

Nick Parker21-Mar-04 9:02

Nick Parker

21-Mar-04 9:02

Check out SetScrollPos and GetScrollPos.

- Nick Parker
My Blog | My Articles

Code Writing

nynny21-Mar-04 8:22

nynny

21-Mar-04 8:22

Hi members,
I am having a problem in writing a program that will generate a billing statement for a customer. How can I declare gas used in this program?

Natural GasTex Company charges their customers based on the amount of gas that they consumed. The company uses the following table to compute charges.

Gas used (in thousands cubic feet)
Rate

First 20
$16.48

Next 5
$1.19 per thousand cubic feet

Next 7
$0.79 per thousand cubic feet

Above 32
$0.39 per thousand cubic feet

Nyn

Re: Code Writing

Nick Parker21-Mar-04 8:44

Nick Parker

21-Mar-04 8:44

This appears to be a homework assignment. If you have specific questions people are willing to help you, however they will not do your homework for you as you are only cheating yourself in the end.

- Nick Parker
My Blog | My Articles

Re: Code Writing

Prakash Nadar21-Mar-04 14:18

Prakash Nadar

21-Mar-04 14:18

nynny wrote:
I am having a problem in writing a program that will generate a billing statement for a customer.

woah... how much are you charging ur customer ? OMG | :OMG:

MSN Messenger.
prakashnadar@msn.com

Re: Code Writing

Christian Graus21-Mar-04 14:59

Christian Graus

21-Mar-04 14:59

I'm happy to do this for you, my rate is $200 an hour. If you ever want to make that sort of money yourself, I suggest doing your own homework.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Code Writing

alex.barylski21-Mar-04 15:49

alex.barylski

21-Mar-04 15:49

At first, I was fooled...then I read the other posts went back and read it again. Realizing the second time it was probably homework, I laughed and decided not to offer my solution. And to think I was wondering how anyone could get a client and not be capable of solving such a trivial problem.

Cheers Smile | :)

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Re: Code Writing

Christian Graus21-Mar-04 15:55

Christian Graus

21-Mar-04 15:55

The question is, how many CP 'members' are loser like this who join, and run away when they find out they have to do their own homework ?

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Code Writing

David Crow22-Mar-04 7:47

David Crow

22-Mar-04 7:47

Christian Graus wrote:
...how many CP 'members' are loser like this...

A little naive maybe, but I would hardly call him/her a loser.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Code Writing

alex.barylski22-Mar-04 9:09

alex.barylski

22-Mar-04 9:09

To many

How do I print my voice mail?

Google is your friend

Michael P Butler21-Mar-04 22:12

Michael P Butler

21-Mar-04 22:12

http://cms.dt.uh.edu/Faculty/ChenP/class/1410/Project1.htm[^]

LOL

Michael

But you know when the truth is told,
That you can get what you want or you can just get old,
Your're going to kick off before you even get halfway through.
When will you realise... Vienna waits for you? - "The Stranger," Billy Joel

Re: Google is your friend

Maximilien22-Mar-04 1:02

Maximilien

22-Mar-04 1:02

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Google is your friend

Antony M Kancidrowski22-Mar-04 6:23

Antony M Kancidrowski

22-Mar-04 6:23

hehehe, Amazing what google can find you! Big Grin | :-D

Ant.

Re: Google is your friend

Christian Graus22-Mar-04 9:11

Christian Graus

22-Mar-04 9:11

We were working on an online ordering system for a client and had a version online for them to test. Google found it, it was quite a kerfuffle. We, as a result, learned how to mark a site so google won't index it.

Christian

I have drunk the cool-aid and found it wan and bitter. - Chris Maunder

Re: Google is your friend

alex.barylski22-Mar-04 9:11

alex.barylski

22-Mar-04 9:11

Thats pretty good...what exactly di dyou look for when you found that? Smile | :)

Cheers

How do I print my voice mail?

Re: Google is your friend

Curi0us_George22-Mar-04 9:20

Curi0us_George

22-Mar-04 9:20

He wasn't very sneaky. He stole the description directly from the page. Grab the first four words (or the whole line, whatever), and Google will give you exactly one result.

http://www.google.com/search?&q=Natural%20GasTex%20Company%20charges

Re: Google is your friend

alex.barylski22-Mar-04 17:21

alex.barylski

22-Mar-04 17:21

thats pretty lazy...

If you dislike programming that much, why take the course in the first place..

How do I print my voice mail?

Re: Google is your friend

Michael P Butler22-Mar-04 9:20

Michael P Butler

22-Mar-04 9:20

Hockey wrote:
Thats pretty good...what exactly di dyou look for when you found that?

I simply put his question into google

Natural GasTex Company charges their customers [^]

Perhaps we should alter the forums so that they do a google when a message is posted. Clippy can then appear and say "You appear to want somebody to do your homework. You won't get any help with that"

Big Grin | :-D

Michael

But you know when the truth is told,
That you can get what you want or you can just get old,
Your're going to kick off before you even get halfway through.
When will you realise... Vienna waits for you? - "The Stranger," Billy Joel

Re: Google is your friend

alex.barylski22-Mar-04 17:20

alex.barylski

22-Mar-04 17:20

Michael P Butler wrote:
Perhaps we should alter the forums so that they do a google when a message is posted. Clippy can then appear and say "You appear to want somebody to do your homework. You won't get any help with that"

Yeah really Smile | :)

How do I print my voice mail?

Re: Code Writing

alex.barylski21-Mar-04 15:45

alex.barylski

21-Mar-04 15:45

Yer too funny Wink | ;)

Cheers

How do I print my voice mail?

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