Re: displaying a variable's value every 30 seconds - C / C++ / MFC Discussion Boards

displaying a variable's value every 30 seconds

Keylee7177-Apr-04 6:49

7-Apr-04 6:49

I've been asked to display a variable's value every 30 seconds on stdout in the same display position on the same line of stdout without advancing the display position. I'm new to C++ and don't know how to begin with this. Please help! Sigh | :sigh:

Re: displaying a variable's value every 30 seconds

Daniel Turini7-Apr-04 7:23

Daniel Turini

7-Apr-04 7:23

To go to the start of the line again, simply output a '\r' char...

I see dumb people

Re: displaying a variable's value every 30 seconds

beetung7-Apr-04 8:33

beetung

7-Apr-04 8:33

10 lines max with a javascript excluding all tags

Re: displaying a variable's value every 30 seconds

Daniel Turini7-Apr-04 8:33

Daniel Turini

7-Apr-04 8:33

Keylee717 wrote:
That's just a carriage return.
And why do you think it has this name?
Try this code:

for (int i = 0; i < 1000; i++)
{
    std::cout << i << '\r';
    Sleep(30 * 1000);
}

I see dumb people

Re: displaying a variable's value every 30 seconds

Daniel Turini7-Apr-04 9:23

Daniel Turini

7-Apr-04 9:23

sorry, forgot to mention: windows.h

I see dumb people

Re: displaying a variable's value every 30 seconds

Daniel Turini7-Apr-04 9:49

Daniel Turini

7-Apr-04 9:49

Keylee717 wrote:
It doesn't change the value after 30 seconds though.
Sorry, I didn't understand your problem... Isn't it printing different values each 30 seconds?

I see dumb people

Re: displaying a variable's value every 30 seconds

David Crow7-Apr-04 10:43

David Crow

7-Apr-04 10:43

Keylee717 wrote:
That's just a carriage return. I need to stay on the original line.

Which is what \r does. Had \n also been speciifed, then it would have gone to the beginning of the next line.

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

Re: displaying a variable's value every 30 seconds

Renjith Ramachandran7-Apr-04 9:16

Renjith Ramachandran

7-Apr-04 9:16

if you are in DOS mode
you can use
gotoxy(x, y) function

like
gotoxy(24, 12);
cout<<"First 30 ";
//30 sec delay logic here
gotoxy(24, 12);
cout<<"Second 30 ";

that will output in the same screen coordinate

The returned pointer may be temporary and should not be stored for later use.

Re: displaying a variable's value every 30 seconds

toxcct7-Apr-04 10:26

toxcct

7-Apr-04 10:26

no, that function doesn't exist under VC++. that is a borland one... forget it, it is a non-standard (non-ANSI) function.

TOXCCT >>> GEII power

Re: displaying a variable's value every 30 seconds

avenger_sb258-Apr-04 12:45

avenger_sb25

8-Apr-04 12:45

why r all ppl saying about '\r' when there is a smart option of '\b'. IT PUTS A BACKSPACE AND TAKES U WHERE U WERE.

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

UNICODE problem

jancsi7-Apr-04 6:32

jancsi

7-Apr-04 6:32

Hi all

I have the following problem :
I cannot set dialog items text (like STATIC TEXT) to UNICODE (CWnd::SetWindowText is working but the displayed text is not readable ) .Interesting is that when I call SetWindowText directly on the CDialog the dialog's title is readable , but when I call the same method on any dialog element it will display unreadable text.

Anyone has any idea?

xxx

Re: UNICODE problem

PJ Arends7-Apr-04 14:26

PJ Arends

7-Apr-04 14:26

Show some sample code of what you are doing

Sonork 100.11743 Chicken Little

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Within you lies the power for good - Use it!

Conversion...

Anonymous7-Apr-04 6:31

Anonymous

7-Apr-04 6:31

How to convert char to CString... ?

ch[0]
ch[1]
ch[2]

to 1 CString

Re: Conversion...

Ravi Bhavnani7-Apr-04 7:30

Ravi Bhavnani

7-Apr-04 7:30

ch[3] = '\0';
CString strMyString = ch;

/ravi

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Re: Conversion...

Renjith Ramachandran7-Apr-04 8:38

Renjith Ramachandran

7-Apr-04 8:38

like:
char a , b , c;
a='A';
b = 'B';
c = 'C';

CString csFullStr;
csFullStr.Format("%c%c%c", a, b, c);

The returned pointer may be temporary and should not be stored for later use.

can different Desktop post message to each?

tank10257-Apr-04 6:11

tank1025

7-Apr-04 6:11

i have a problem:whether different Desktop can post message to each other?

Re: can different Desktop post message to each?

Mike Dimmick7-Apr-04 6:17

Mike Dimmick

7-Apr-04 6:17

If they're in the same window station, I believe so.

However, I think you're talking about communications between computers, in which case you need to use some form of Remote Procedure Call.

Stability. What an interesting concept. -- Chris Maunder

playing a movie in a dialog-box?

cristane7-Apr-04 6:06

cristane

7-Apr-04 6:06

Hi. I have a question: how can I play a mpeg movie inside a dialog box, from a SDI application?

I tried the "easy" way... and it doesn't work...

(here's the "easy" way: after creating the dialog box, and the OnSomething function, and importing CMediaPlayer, I wrote this code:

CMediaPlayer dlg;
dlg.CreateWindow (.....yadda yadda...);
dlg.ShowWindow (WS_SHOW);
dlg.m_player.Open ("Test.mpeg");
dlg.m_player.Play ();

The funny thing is.... it works fine for a dialog-based application - when I write the last 2 lines of the above code, in the OnInitInstance() function.

Any suggestion welcome. (as you can see, I'm not a great programmer, so please don't laugh )

Thanks.

We are accidents waiting to happen...

Re: playing a movie in a dialog-box?

Prakash Nadar7-Apr-04 6:19

Prakash Nadar

7-Apr-04 6:19

OnInitInstance is related to the application thread... there i guess it would have any effect.

humm as far i have understood this could be the solution..

Create an sdi application with form view and then place the mov player and do the coding for it like a normal dialog application in the view.

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pointer to virtual function

RalfPeter7-Apr-04 5:56

RalfPeter

7-Apr-04 5:56

Hi all,
this is the error I'm getting:

"error C2276: '&' : illegal operation on bound member function expression",

Apparently, this is due to assigning a pointer to a virtual function, yet I do not have any function declared virtual. Does any one know a way around this problem? Is there a way to force a function not to be virtual? Here's a snippet of my code:

In .h
…
class MyClass
{…
int VBGCalc(const gsl_vector *x, void *params, gsl_vector *f, gsl_matrix *J);
int VBGPartials(const gsl_vector *x, void *params, gsl_matrix *J);
int VBGFunct(const gsl_vector *x, void *params, gsl_vector *f);

int VBGF(void); //problem in this function
…
};

in .cpp

int MyClass::VBGF(void)
…
f.f = &VBGFunct; //offending code
f.df = &VBGPartials; //ditto
f.fdf = &VBGCalc; //ditto
…

return 1;
}

int (* f) (const gsl_vector * x, void * params, gsl_vector * f);
gsl_vector and gsl_matrix are struct variables.

Thanks,
Ralf.

ralf.riedel@usm.edu

Re: pointer to virtual function

Mike Dimmick7-Apr-04 6:24

Mike Dimmick

7-Apr-04 6:24

You can't assign a member function pointer to an ordinary function pointer. The type of VBGFunct is int (MyClass::*) (const gsl_vector *, void *, gsl_vector *). You can't take the address of a member function pointer.

You would have to either declare f as int (MyClass::*f)( /*etc*/ ) or declare your functions as static. If you do the first, you must call them using the ->* or .* notation, e.g.:

(this->*f)(pX, pParams, pF)

If you do the second, you won't be able to access any non-static members of MyClass.

If you're trying to provide polymorphism, it's easier to either do run-time polymorphism via inheritance, or compile-time polymorphism using templates.

Stability. What an interesting concept. -- Chris Maunder

Re: pointer to virtual function

Prakash Nadar7-Apr-04 6:29

Prakash Nadar

7-Apr-04 6:29

member functions are of __THISCALL so i guess assigning a pointer to the method could of some problem and also using it..

try making the methods static i guess then it will work... But then i dont know wheather making them static is in ur software design.

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Re: pointer to virtual function

RalfPeter7-Apr-04 11:13

RalfPeter

7-Apr-04 11:13

Made it static. Much easier. Thank you all,
Ralf.

ralf.riedel@usm.edu

C++ & MFC -> Listbox Question

Qualvis7-Apr-04 5:45

Qualvis

7-Apr-04 5:45

Hi,

How can I add something to a listbox, AFTER it's initialized?
First, I use this code:

BOOL CDialog1::OnInitDialog()
{
CDialog::OnInitDialog();
m_ListBox.AddString("jef");
return true ;
}

and this works fine. But I want to be able to add other items afterwards (to be precise, I would like to be able to show the user which webcams are available.)

So I made a function:

void CCamDialog::AddListBox()
{
m_ListBox->AddString("camera");
}

But this gives an error (debg assertion failed).

any ideas?

thanks

Re: C++ & MFC -> Listbox Question

David Crow7-Apr-04 5:47

David Crow

7-Apr-04 5:47

When is AddListBox() getting called? If it is before the listbox window actually exists, you obviously cannot add to it.

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