C / C++ / MFC Discussion Boards

Re: How Can I Set Items' Images of Toolbar

viliam4-Nov-02 0:55

4-Nov-02 0:55

Try this:
CToolBar::LoadBitmap()
CToolBar::SetBitmap()

or call CToolBar::GetToolBarCtrl()
And then access single items – more: CToolBarCtrl member functions
Viliam

Re: How Can I Set Items' Images of Toolbar

IMiracle4-Nov-02 1:03

IMiracle

4-Nov-02 1:03

I means that one item have its own one image.
A toolbar has several images, not one bitmap to all items.

"multi-master"

Anonymous4-Nov-02 0:41

Anonymous

4-Nov-02 0:41

I've got this for my tute question!

A large organisation has offices in several countries around the world. Explain why it is desireable for the organisation's directory service to be "multi-master"

Could any one please enlighten me! Thanks.

Re: "multi-master"

Maximilien4-Nov-02 2:52

Maximilien

4-Nov-02 2:52

Huh ?! I assume that it got to be related to the Active Directory thing, just read about it, it's bound to be explained somewhere in there .

Max.

Generating a short delay (a few ms)

LittleYellowBird3-Nov-02 23:58

LittleYellowBird

3-Nov-02 23:58

I'm trying to generate a short delay of just a few ms, which I need because I am controling a box on the serial port which is very slow and the input is un-buffered so I need to pad the data.

I am using Sleep(x), where x is the number of ms. However, I get a much longer delay than I need, ie Sleep(1) gives me 70ms!

Anyone got any ideas of how I can generate a short delay reliably?

Thanks,

Ali

Re: Generating a short delay (a few ms)

Vagif Abilov4-Nov-02 0:30

Vagif Abilov

4-Nov-02 0:30

You can try Sleep(0), it causes the thread "to relinquish the remainder of its time slice to any other thread of equal priority that is ready to run."

Vagif Abilov
MCP (Visual C++)
Oslo, Norway

Hex is for sissies. Real men use binary. And the most hardcore types use only zeros - uppercase zeros and lowercase zeros.
Tomasz Sowinski

Re: Generating a short delay (a few ms)

LittleYellowBird4-Nov-02 2:21

LittleYellowBird

4-Nov-02 2:21

Thanks for the suggestion, I'm not sure it will give consistent enough results - I'll look in to it though.

Thanks,

Ali

Re: Generating a short delay (a few ms)

Gary Kirkham4-Nov-02 11:26

Gary Kirkham

4-Nov-02 11:26

You didn't say what operating system you were using. I doesn't answer your question, but you may find the following article interesting...

http://www.codeproject.com/system/simpletime.asp

Gary Kirkham

A working Program is one that has only unobserved bugs

Re: Generating a short delay (a few ms)

LittleYellowBird5-Nov-02 3:15

LittleYellowBird

5-Nov-02 3:15

Looks like an interesting article, thanks for the tip.

Cheers,

Ali

Re: Generating a short delay (a few ms)

viliam4-Nov-02 0:33

viliam

4-Nov-02 0:33

I am afraid there is no way how to suspend process on accurate time.
(Windows are not real - real-time system)
The easiest way is use traditional way – run some loop
(and be on appropriate priority)
And check time...
Something like:
.
.
dwA = GetTickCount();
while(1)
{
dwB = GetTickCount();
if( (dwB-dwA) >= dwTimeout)
break;
}

This is not nice way but sometime can help.
Anyway times about 1 ms are probably unreachable.
Viliam

Re: Generating a short delay (a few ms)

LittleYellowBird4-Nov-02 2:18

LittleYellowBird

4-Nov-02 2:18

Using GetTickCount() is a great idea. I just checked the help and it returns the number of ms since start up, so as you suggest I can use it in a loop to make a basic timer.

I agree that 1 ms is impractical but if I try for 1 ms and get 2 ms or 3ms or even 4ms, that woud be far better than 70+ ms!

Thanks for the help,

Ali

Re: Generating a short delay (a few ms)

Brigg Thorp4-Nov-02 2:28

Brigg Thorp

4-Nov-02 2:28

One thing you have to watch out for. If you keep your computers on all the time, the rollover of the time could effect your calculation (e.g the start time could be greater than the end time). You just have to put in checking for this.

Brigg Thorp
Software Engineer
Timex Corporation

Re: Generating a short delay (a few ms)

LittleYellowBird4-Nov-02 3:02

LittleYellowBird

4-Nov-02 3:02

Good point, as you say pretty easy to check for, I'll make sure I do.

Thanks,

Ali

Re: Generating a short delay (a few ms)

includeh104-Nov-02 1:10

includeh10

4-Nov-02 1:10

as i know, serial port needs a thread (call it thread A) to read data.
u say "delay", delay what? for what?
i assume that u want "delay" (by Sleep) main thread (parent thread of thread A) to active Thread A. this is not correct in concept, the 70ms must be got from Thread A, the time is meaningless, just forget it.

only choice i think is to set a timer (few ms) in main thread for delay, then kill the timer.

includeh10

Re: Generating a short delay (a few ms)

LittleYellowBird4-Nov-02 2:10

LittleYellowBird

4-Nov-02 2:10

includeh10 wrote:
u say "delay", delay what? for what?

What I need is a delay between sending bytes because the receiving device is too slow and cannot buffer data coming in. If I send bytes too quickly they get ignored. But if I have really big delays then it takes ages to set up.

It looks like this is not possible, not sure what I am going to do.

Thanks for the advice,

Ali

Re: Generating a short delay (a few ms)

includeh104-Nov-02 2:25

includeh10

4-Nov-02 2:25

i used communication port for years, do u use a event to check if sending buffer is empty?

includeh10

Re: Generating a short delay (a few ms)

LittleYellowBird4-Nov-02 3:09

LittleYellowBird

4-Nov-02 3:09

includeh10 wrote:
do u use a event to check if sending buffer is empty?

Yes, I send a block of data. I can see that the sending buffer is empty. Then I want to leave a gap of 1 or 2 ms to let the receiving device process the data before I send the next block of data.

If I do not leave a gap at all, then the receiving device ignores the first block of data and it is lost.

If I leave a big gap like 70ms to 100ms, I can't send the data quickly enough, because most of the time is used up by the gaps.

I think I may be able to use GetTickCount to create a basic timer, (see above reply). I think I will try that.

Thanks for your help,

Ali

Re: Generating a short delay (a few ms)

includeh104-Nov-02 4:26

includeh10

4-Nov-02 4:26

communication port is not an easy job, u need to generate a good process in one app then for forevere (next apps).
i suggest u use 2 threads (sibling threads). one thread keeps all sending data in a buffer, another one is used for receiving data and deals with events.
u can use sleep between sibling threads to control working process.
if use many threads, make sure they are terminated properly (i used over 100 threads in one app). do not use CloseHandle() etc to interrupt threads, especially buffering threads. let threads exit natually, otherwise u may see exceptions often.

includeh10

Re: Generating a short delay (a few ms)

LittleYellowBird5-Nov-02 3:18

LittleYellowBird

5-Nov-02 3:18

includeh10 wrote:
communication port is not an easy job

Yes, thats true, and to be honest I have only one thread at the moment so that is obviously not helping. Looks like its time to look at threads!

Thanks for the advice,

Ali

Re: Generating a short delay (a few ms)

Roger Allen4-Nov-02 7:09

Roger Allen

4-Nov-02 7:09

I did something similar for a data collection thread that has to get spectra from a Diode array detector on set intervals. The way I did it was to the set thread priority very high (TIME_CRITICAL), so when the Sleep() completed, that thread was given control again. As it spent most of its time in a sleep() state it did not have any adverse effect of system performance.

Some of the oce envolved was:

RunThread->SetThreadPriority(THREAD_PRIORITY_TIME_CRITICAL) ;


	FILETIME time1;
	FILETIME time2;


	::GetSystemTimeAsFileTime(&time1) ;		// get the current time
	
	while (...)
		{
		::GetSystemTimeAsFileTime(&time2) ;		// get the current time
		delay = (m_spectra_frequency * spectra_collected) - CalculateElapsedTime(&time1, &time2) ;
		if (delay >= 0.001)
			Sleep((unsigned long)(delay * 1000.0)) ;
		}




double CalculateElapsedTime(FILETIME *start, FILETIME *current)
{
	double	elapsed_time ;
	__int64	st ;
	__int64	ct ;
	__int32	*p ;

	p = (__int32*)&st ;
	*p++ = start->dwLowDateTime ;
	*p = start->dwHighDateTime ;
	//st = (start->dwHighDateTime << 32) + start->dwLowDateTime ;
	p = (__int32*)&ct ;
	*p++ = current->dwLowDateTime ;
	*p = current->dwHighDateTime ;
	//ct = (current->dwHighDateTime << 32) + current->dwLowDateTime ;
	elapsed_time = (double)(ct - st) ;
	elapsed_time /= 10000000.0 ;	// convert from 100ns intervals to seconds
	return elapsed_time ;
}

It may be of use

Roger Allen
Sonork 100.10016

I have a terminal disease. Its called life!

Re: Generating a short delay (a few ms)

LittleYellowBird5-Nov-02 3:29

LittleYellowBird

5-Nov-02 3:29

Thanks for the advice. Believe it or not I've got away with just one thread in all my apps up to now! But it looks like I cannot run away any longer, now is the time to look at threads.

I think I can see what you are explaining, its nice to have the code snippet to look at - I'll give it a go.

If you see some more questions about threads from me in the coming days you'll know it hasn't gone well! Smile | :)

Thanks again,

Ali

Change data format from CString to int

ooosawaddee33-Nov-02 23:35

ooosawaddee3

3-Nov-02 23:35

If I have this below CString data and I want to change it format to int.

Example:
CString data_str = "1487";
int data_int;

I want

data_int = 1487

Do you know how to do that?

Re: Change data format from CString to int

ian mariano3-Nov-02 23:43

ian mariano

3-Nov-02 23:43

Sometimes the C runtime comes in handy: atoi()[^]

"The greatest danger to humanity is humanity without an open mind."
- Ian Mariano - http://www.ian-space.com/

Re: Change data format from CString to int

RChin3-Nov-02 23:48

RChin

3-Nov-02 23:48

use:

data_int = atoi( (LPCTSTR)data_str );

or even better use:

data_int = _ttoi( (LPCTSTR)data_str ); // unicode safe

MSI files problem

Anthony B.3-Nov-02 23:25

Anthony B.

3-Nov-02 23:25

I have used Visual Studio Installer to produce some MSI files
to install my applications.

I some PCs, where only WINNT or WIN2K OS is installed (MS office
not installed)the MSI file cannot be executed.

Does someone knows which application or DLL must be installed in
the target machine in order to allow the MSI file execution ???

Thank a lot !!!

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