Re: graphics in c/c++ - C / C++ / MFC Discussion Boards

фил22-Apr-04 1:56

22-Apr-04 1:56

i need help with my timeouts. i can get my program to read/write single bytes, but the problem is a function related with the hardware i'm using.

you send the command and the hardware will enter a loop sending you each 3ms 7 bytes.

i can't set the timeouts properly in order to receive all those bytes (the most important thing is that i don't loose any bytes!)...

can anybody please help me??

thank you in advance...

Я люблю русский языкь!

Problem with CStdioFile

Stojan7822-Apr-04 1:36

Stojan78

22-Apr-04 1:36

Hello all

I'm pretty new on C++ and I have a problem. The thing is that I want to write a CString to a CStdioFile and be able to read the string from the file. All I have done so far is a little testprogram, just to se if it worked. It did not! Problem: I get a lot of junk text in my file and when I read from the file. Here is the code, I would be very greatful if anyone could help me a bit.

CStdioFile file;
CString filnamn = "Temp.txt";
CFileException fileException;
char buf1[] = "Hej hej\n";
char buf2[] = "Jag heter henrik\n";
CString rad = "";
CString rad1 = "Hej hej";
CString rad2 = "Jag heter henrik";

if (!file.Open(filnamn, CFile::modeCreate | CFile::modeReadWrite, &fileException))
{
TRACE("Can't open file %s, error = %u\n",
filnamn, fileException.m_cause);
}

file.WriteString(rad1 + '\n');
file.WriteString(rad2 + '\n');
file.ReadString(rad);
printf(rad, "%s");
file.Close();

Re: Problem with CStdioFile

Steve S22-Apr-04 1:53

Steve S

22-Apr-04 1:53

You need to move the file pointer (where in the file you're reading/writing).

Try file.SeekToBegin() before trying to read...

Steve S

Re: Problem with CStdioFile

jmkhael22-Apr-04 1:53

jmkhael

22-Apr-04 1:53

And your printf is erronous

try a printf((LPCTSTR)rad);

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: Problem with CStdioFile

RChin22-Apr-04 1:53

RChin

22-Apr-04 1:53

Stojan78 wrote:
file.WriteString(rad1 + '\n');
file.WriteString(rad2 + '\n');
file.ReadString(rad);

Your problems lies with the above statement.
Try this:

<br />
file.WriteString(rad1 + '\n');<br />
file.WriteString(rad2 + '\n');<br />
file.SeekToBegin(); // move file pointer to begining of file.<br />
file.ReadString(rad);<br />

I Dream of Absolute Zero

Re: Problem with CStdioFile

Stojan7822-Apr-04 2:11

Stojan78

22-Apr-04 2:11

Thanks a lot all. It now works just fine...

graphics in c/c++

kcal22-Apr-04 1:36

kcal

22-Apr-04 1:36

i am using visual studio to make some histogram graphs and pie graphs of standered divation but the programme does not recognize the graphics.h header file. how should i make the graphs and please tell what should i do to this heard file (graphics)

graphics in c/c++

Re: graphics in c/c++

Ian Darling22-Apr-04 2:06

Ian Darling

22-Apr-04 2:06

Have a look at Windows GDI instead. You'll be most interested in the DrawLine function, I expect.

If you're on a suitably recent version of Windows, GDI+ (or System.Drawing in .NET) might be more suitable.

GDI:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winprog/winprog/graphics_device_interface.asp[^]

GDI+:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/gdicpp/GDIPlus/GDIPlus.asp

Ian Darling
"If we've learned anything from history, it's that those who feed trolls are condemned to repetitive conversations. Or something like that." - Eric Lippert

Change Style subsequent on CSlideCtrl

AnTri22-Apr-04 1:13

AnTri

22-Apr-04 1:13

How can I change the Style of an CSlideCtrl subsequent? I need this, because some settings cannot be set on the dialog editor...!

Problem of setting size and position of scrollbar's thumb

bg2sc22-Apr-04 1:06

bg2sc

22-Apr-04 1:06

Thank you for reading this.
Now I want to keep the height and position of vertical scrollbar's thumb all
the time,so I used this Frown | :(

m_ctrlTree' is a TreeListView control)
----------------------------
const int nBar = SB_VERT;
SCROLLINFO si = {0};
si.cbSize = sizeof(si);
si.fMask = SIF_ALL;
m_ctrlTree.GetScrollInfo(nBar, &si);
si.nMax = si.nPage * 2;
si.nPos = (int)si.nPage/2;
m_ctrlTree.SetScrollInfo(nBar, &si, TRUE);
-----------------------------
I placed that block in the 'OnPrePaint' event of the tree control and it really works,but
problem is that when resizing the TreeListView window or expanding a
node, it scrolls madly,perhaps always scrolls to the last record,this is not what I
want.

Is the calculate method right?And where should I place the
SetScrollInfo(nBar, &si, TRUE)to control the Thumb?

Best reguards.
de BG2SC

How do i detect user inactivity ?

rallister22-Apr-04 1:02

rallister

22-Apr-04 1:02

Hi,
in an application that i'm developping, i need to know if there are some user activities at any given time, such as the mouse being moved or the keyboard being used.

Is there any other smarter way to know how, that there are no user activity on the system and how long he was not active. Such a behaviour is used by application for IM, when they set the "away" message !

Thanks in advance for any hints and best regards
Richard

Re: How do i detect user inactivity ?

jmkhael22-Apr-04 1:10

jmkhael

22-Apr-04 1:10

Check OnIdle( LONG lCount ); for MFC

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: How do i detect user inactivity ?

rallister22-Apr-04 1:18

rallister

22-Apr-04 1:18

Hi,
i'm not using mfc in my application ;o) !
So please provide a solution without mfc !
Thx in advance and best regards
Richard

Re: How do i detect user inactivity ?

jmkhael22-Apr-04 1:48

jmkhael

22-Apr-04 1:48

From MSDN about OnIdle

OnIdle is called in the default message loop when the application’s message queue is empty. Use your override to call your own background idle-handler tasks.

Why not do the "same" in your main loop?
When no messages are being treated treat Call an OnYourIdle Function

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: How do i detect user inactivity ?

David Crow22-Apr-04 2:19

David Crow

22-Apr-04 2:19

Check out GetLastInputInfo().

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

Re: How do i detect user inactivity ?

hasansheik22-Apr-04 3:21

hasansheik

22-Apr-04 3:21

If you are using MFC based application u can track it by overriding OnIdle method of CWinApp class.
for direct win32 application u can use WinProc method to track any message is posted on the message queue of the application.

One Best method is, Through Hook. write a WH_MESSAGE hook and do your work fine

I hope it will help you

thanks

Re: How do i detect user inactivity ?

V.22-Apr-04 3:28

22-Apr-04 3:28

Maybe one note on the onidle loop.
It will use a lot of cpu % usage!
You can solve this by setting a start time in your onidle (and then tell it to stop working) and starting a thread which will test this starttime against the currenttime. if a certain time has passed ... (take some action).
Put a Sleep in your thread to keep the cpu % usage down.

Have fun ...

Re: How do i detect user inactivity ?

peterchen22-Apr-04 4:25

peterchen

22-Apr-04 4:25

As already suggested, GetLastUserInputInfo() on W2K+ systems.
Otherwise you could modify the main message loop, and take the time stamps of hincoming mouse/keyboard messages.
Another option would be a Mouse/Keyboard hook inside your process, that simply resets a timer. This seems the most independent solution (and not too complicated), but personally I would avoid a hook unless it's the only way.

or you just check if the space key is permanently down, and there are snoring noises from the MIC IN. Wink | ;)

Flirt harder, I'm a Coder

mlog || Agile Programming | doxygen

Re: How do i detect user inactivity ?

Rick York22-Apr-04 10:12

Rick York

22-Apr-04 10:12

This article demonstrates one method : http://www.codeproject.com/dll/trackuseridle.asp[^]

__________________________________________
a two cent stamp short of going postal.

Shell question (I Guess)

Deian22-Apr-04 0:47

Deian

22-Apr-04 0:47

I want to be able to display properties for file or folder, as we do when right-clicking over file or folder, I have to display this shell dialog (shell dialog I Guess), but my search in msdn and here at CP does not give any results. Does anyone know how to do that or have information link?

Thanks in Advance!

Re: Shell question (I Guess)

_Magnus_22-Apr-04 1:00

_Magnus_

22-Apr-04 1:00

Try ShellExecute with the verb "Properties"

/Magnus

- I don't necessarily agree with everything I say

Re: Shell question (I Guess)

Deian27-Apr-04 4:07

Deian

27-Apr-04 4:07

Doesent seem to work Frown | :(

Bizzare problem reading large number of files

Raul00722-Apr-04 0:34

Raul007

22-Apr-04 0:34

Following is the code snippet i am working with.
miNumDataFile denotes number of datafiles
msarrDataFile[iloop] denotes the file path and name.

I am opening around 3000 fines in binary mode and
reading all the records in each file using fread. total file size
around 187mb with 1366218 rows.
its a simple c exe.

on the first run it takes 48 secs.
on the seond run it takes 2 secs!!!!!!!!!.

my question is why is happening. each time i reboot my pc
the same phenomenon happens. WHY??????

for(int iloop=0;iloop

Re: Bizzare problem reading large number of files

jmkhael22-Apr-04 0:38

jmkhael

22-Apr-04 0:38

The OS does a caching for you
does it bother you?

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: Bizzare problem reading large number of files

Raul00722-Apr-04 18:17

Raul007

22-Apr-04 18:17

Thanks Papa for your reply.
I was not sure what was happening.
Now even if the OS is doing the caching part, I have 2 questions.
Will this happen in every OS. and further more some times it takes 1-2 secs to read files (total size 200 MB). that whats bothers me. 1/2 secs is really low, for reading and processing 200MB file wont you think!!
Anyway i am planing it run this component on a web sever. and a page will call this to show the results of this component.
thats why i am so worried about this thing..

Thanks a lot anyway...

Apratim

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