C / C++ / MFC

16-Jun-04 7:52

I looked through Word's Save As list and did not see TIFF as an option. That's not to say it cannot be done, but having not ever done this, my initial response is "Is it possible, since Word does not offer such a conversion?"

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

using substring in VC++

swerajan16-Jun-04 7:47

swerajan

16-Jun-04 7:47

I have a char buffer[20000] defined. I need to extract words from the buffer which has a string of characters which varies in length. I am not able to use substring to extract the word from the start position. how do extract a string from within a string in VC++.

David Crow16-Jun-04 7:49

16-Jun-04 7:49

_strtok() comes to mind. Or how about strcspn()? If I'm way off, then I do not understand your question.

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

swerajan16-Jun-04 8:01

swerajan

16-Jun-04 8:01

strtok tokenizes the string, and strcspn gives the starting position of the string i am searching. I want to extract the string given the starting position and number of characters to extract. say for example i have "This is a test sample", using substring i should be able to extract sample.

substring in itself doesn't work in VC++. i don't know what equivalent is in VC++.

David Crow16-Jun-04 8:05

16-Jun-04 8:05

How about:

char *str = "This is a test sample";
char sub[7] = {0};
strncpy(sub, &str[15], 6);

memcpy(sub, &str[15], 6);

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

Critical Section question

toxcct16-Jun-04 9:54

toxcct

16-Jun-04 9:54

mid()

TOXCCT >>> GEII power

kfaday16-Jun-04 7:25

kfaday

16-Jun-04 7:25

Hi I'm designing a multiclient drawing board. There's a pencil. When you click (OnLButtonDown) on the pencil over an area, CPoints are added to a CPoint list(OnMouseMove), and when you release the mouse button (OnLButtonUp), a (-1,-1) is sent to the list.

I sent that, so that in the OnPaint function, LineTo's are called for every point of the list, and when you get a (-1,-1) it means that the line ends.

When you release the mouse button(OnLButtonUp), the list is sent to the other drawing board.

The problem is that while you are drawing (without release the mouse button), and the other person draws something, when he realeases the mouse button, the list is sent to the other person, and i don't want that to happen.

So i thought of CCritical Section. The drawing board, has the list of CPoints, and i wanted the board not to receive while you are drawing.

So i declared in the drawing board class:
CCriticalSection CritSect;
And in the OnLButtonDown, i call CritSect.Lock(), and in OnLButtonUp, i call CritSect.UnLock(), hoping that when you are drawing, a list wouldn't be inserted to your list when you are drawing. but that doesn't happen.

Do you have any ideas of what i'm doing wrong? perhaps the CCriticalSection approach is wrong.

thank you very much for your help!.

Blake Miller16-Jun-04 13:27

Blake Miller

16-Jun-04 13:27

Depends on who your clients are and how they are calling into your program.
Do you have multiple threads running?

If no, then you need something more like a code for ownership, that is not a 'thread' protector. You can somehow identify your clients by a code, and then only allow the button down to assign a client to the list if no other client is using the list. And only respond to the button up if the client already owns the list.

kfaday16-Jun-04 14:31

kfaday

16-Jun-04 14:31

it's only a thread.
The program is only one to one, there are only 2 clients connected at a time.
Blake Miller wrote:
only allow the button down to assign a client to the list if no other client is using the list. And only respond to the button up if the client already owns the list.

how could i do that?

Blake Miller16-Jun-04 14:41

Blake Miller

16-Jun-04 14:41

If you can not identify your clients, you will never sort this out.
Suppose you have a variable called PointListOwner, and you can assign PLO_NONE, PLO_CLIENT_ONE, or PLO_CLIENT_TWO, then initially you set it to PLO_NONE.

Then, when you get the button down message, you figure out which client the message came from and assign the variable that client's identifier (assuming no client currently owns the list). Then when another button down message comes in, if it is not client who owns the list, ignore it. When a button up message comes in, then if it is not client who owns it, ignore it. If the button up is the client who owns list, then draw the lines and then set the owner back to none, so the other client, or the same one, can own the list on the next button down.

Since you only have one thread, no mutex, criticalsection, etc. is going to help you with blocking access.

I don't knwo how your server is accepting the client messages, but you need to factor in a mechanism for the messages to be associated with each client.

Rodrigo Pinto Pereira de Souza

kfaday16-Jun-04 15:35

kfaday

16-Jun-04 15:35

that could be what i'm looking for.. i'll see about it. thanks

a newbie question

Nelson L.16-Jun-04 6:33

Nelson L.

16-Jun-04 6:33

Hi,

I would like to update the display in the CSTestView if the OK botton on CParaDlg is pressed, how to initiate the update?

void CParaDlg::OnOK()
{
CString msg = "checked";
AfxMessageBox(msg);
CDialog::OnOK();
}

void CSTestView::OnDraw()
{

}

I will be very appreciated for whatever hint I received.

Regards

Nelson L.

Re: a newbie question

Rodrigo Pinto Pereira de Souza16-Jun-04 7:15

16-Jun-04 7:15

If you are using Doc/View architecture, you should call method UpdateAllViews() from your document object.

example:
GetDocument()->UpdateAllViews();

regards

Rodrigo Pinho Pereira de Souza

Re: a newbie question

Deian16-Jun-04 10:48

Deian

16-Jun-04 10:48

If this is normal dialog, you may check if it's closed with OnOK

void CSTestView::YourCallingFunction()
{
  if(YourDlg.DoModal()==IDOK) // YourDlg is of type CParaDlg
  {
    // update here
  }
}

Getting SID of computer

Bash16-Jun-04 6:27

Bash

16-Jun-04 6:27

Hi,

Could anyone provide an example to get SID (Security Identificator) of local computer ?

Yours sincerely,
Alex Bash

Re: Getting SID of computer

David Crow16-Jun-04 7:48

copy file to another folder

16-Jun-04 7:48

A SID uniquely identifies a user or a group (i.e., a trustee). What makes you think the computer itself has one?

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

elephantstar16-Jun-04 6:24

elephantstar

16-Jun-04 6:24

Hi there,

Can someone tell me how I can copy a file from one folder to another? I was told it was unwise to use the system() function because of security reasons.

Thanks!

palbano16-Jun-04 7:06

palbano

16-Jun-04 7:06

CopyFile()

elephantstar16-Jun-04 10:02

elephantstar

16-Jun-04 10:02

Now why did I think it only works for Visual Basic? Thanks!

David Crow16-Jun-04 7:54

16-Jun-04 7:54

elephantstar wrote:
I was told it was unwise to use the system() function because of security reasons.

To say the least. It's also a holdover from the Unix days. Use CopyFile() as has already been mentioned, or SHFileOperation().

"When I was born I was so surprised that I didn't talk for a year and a half." - Gracie Allen

elephantstar16-Jun-04 10:04

elephantstar

16-Jun-04 10:04

Thanks David!