PC Losing Time - C / C++ / MFC Discussion Boards

Iain Clarke, Warrior Programmer5-Jul-02 1:05

5-Jul-02 1:05

There are a few ways that jump to my mind.

You could override OnGetMinMaxInfo / WM_GETMINMAXINFO to restrict the resizability of your window.

Change the window style (in PreCreateWindow) so you don't have a border to resize.

Override OnNcHitTest / WM_NCHITTEST so it returns HTCAPTION instead on HTTOP etc so you could move your window by dragging on the border rather than resizing it.

A word of warning though. In general, I like being able to resize things, and I'm not alone. Don't break the windows paradigm unless you have a _really_ good reason.

Good luck,

Iain.

iterators & vectors & moral

Bernhard4-Jul-02 22:38

Bernhard

4-Jul-02 22:38

my coworker uses stuff like this all over the code

vector<int> test;
vector<int>::iterator i;

// he wants to skip the first 10 elements
for (i = test.begin() + 10; i < test.end(); ++i)
{
    ....
}

// or stuff like this if he wants to skip the last 10 elements
i = test.begin();
if ( test.begin() + 10 < test.end())
    i += 10;

he asked me something bout this.. and i told him that this is not the proper way to do this (i think of having read that you never never never should another comparison than != for the end() function of a vector).. but actually i don't know any other way to skip 10 elements with one command..

is this proper code ?
what would be a safer way ? (if it isn't proper code ?)

thanks in advance,
bernhard

"I'm from the South Bronx, and I don't care what you say: those cows look dangerous."
U.S. Secretary of State Colin Powell at George Bush's ranch in Texas

Re: iterators & vectors & moral

jmkhael5-Jul-02 3:53

jmkhael

5-Jul-02 3:53

U can very easily run an int counter, and check if in th loop ur not exceding the test.size() + or - offset value in order to take the values, and in order to take the element at the integer i, u can do test.at(i)

Papa
Murex Co.

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: iterators & vectors & moral

Christian Graus5-Jul-02 4:33

Christian Graus

5-Jul-02 4:33

Yes, you should use !=, but you can quite happily use the +, so I see no reason why you can't just replace < with != above. < will work for vector, in any case.

Christian

I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002

Re: iterators & vectors & moral

Joaquín M López Muñoz5-Jul-02 5:42

Joaquín M López Muñoz

5-Jul-02 5:42

(This is rather academic, but anyway) The expression is not valid, even if you use pointers: pointers are only allowed to point one position past the end of a memory block_

char *p=new char[100];
char *p2=p[100]; // OK
char *p3=p2+1; // undefined result

Of course, the line above will work in any compiler that I know of, but the standard does not guarantee it. As for iterators, the situation is the same.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: iterators & vectors & moral

Joaquín M López Muñoz5-Jul-02 4:34

Joaquín M López Muñoz

5-Jul-02 4:34

You're right this is not safe. If you still want to write the stuff in one line, you can use std::distance

i = test.begin();
if ( std::distance(test.begin(),test.end())<10)
    i += 10;

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Writing permission bits to Access Database

Hel4-Jul-02 22:25

Hel

4-Jul-02 22:25

Does anyone know if it is possible to write permission bits to an Access Database and if possible how to go about it. I want to set up a user logon system where they get different permissions and menu options depending on what group they belong to.

PC Losing Time

LittleYellowBird4-Jul-02 21:30

LittleYellowBird

4-Jul-02 21:30

I've written a program in VC++ and when I run it my PC loses time!

Its a 'data recording' type program, reading data in through the serial port once a second, displaying the data on screen and storing the data to harddisk.

I thought maybe the clock would put its self right when I re-booted, but it doesn't. Surely the time is generated from an RTC (Real Time Clock) chip on the motherboard, how can I be affecting that ??????? I'm using 'GetCurrentTime' to read the time.

Any ideas?

Ali

Re: PC Losing Time

Olli5-Jul-02 2:02

Olli

5-Jul-02 2:02

Hi Alison!

Please explain me what is meant with 'loosing time' (how much?? in which amount of time...???)

It's not normal, my app is using lot's of timer-stuff (CTime objects with GetCurrentTime...)

Confused | :confused:

Olli
cause sometimes the world is as strange as me....
Roll eyes | :rolleyes:

Re: PC Losing Time

LittleYellowBird5-Jul-02 2:20

LittleYellowBird

5-Jul-02 2:20

Thanks for replying, its nice to hear that its not normal!

Olli wrote:
how much?? in which amount of time...???

Sorry, realised after I posted that I hadn't said how much time.

I first noticed it when I left it for 1 week running continuously and it lost 28 minutes.

I've run it again this morning and its lost 22 seconds in 2 hours.

If I don't run my code the PC doesn't loose any time. I don't where to start looking.

Ali

Re: PC Losing Time

Olli5-Jul-02 2:44

Olli

5-Jul-02 2:44

How do you 'use' the Time ??????

I use my objects mostly local, like this way:

void SomeFunc()
{
....
CTime theTime = CTime::GetCurrentTime();
....
}

In other cases, e.g. to compare time, i remind the old time in a global object...

BTW: If I want to place a clock in my statusbar, i call the OnTimer() each 0.1 secs, then i compare the CTime::GetCurrentTime() to my oldTime and if it changed, the i start updateting my clock...

Maybe you can show us how in detail you do it, then maybe i can help you..

Alison Pentland wrote:
I've run it again this morning and its lost 22 seconds in 2 hours.

22 secs in s hrs is a lot,... sounds very very strange... Unsure | :~

Olli
cause sometimes the world is as strange as me....
Roll eyes | :rolleyes:

Re: PC Losing Time

LittleYellowBird5-Jul-02 3:16

LittleYellowBird

5-Jul-02 3:16

I'm using it in lots of place, but here's how I get the time ....

CTime timeNow;
timeNow = CTime::GetCurrentTime();

I guess more detail would be good but I'm using CTime alot and I don't know which place is the problem - I don't know which example to give you.

I'm going to run it on a different PC over the weekend, just in case its related to the hardware. I'll let you know Monday how it goes.

Thanks for the interest Smile | :)

Ali

Re: PC Losing Time

Rutger Ellen5-Jul-02 3:34

Rutger Ellen

5-Jul-02 3:34

either you save the time somwhere in your program (using SetSystemTime for instance), after which the system will sync the time automattically or the code you generate somewhere stops interrupts from being processed ( I was not aware that this was still possible, or are you using a win 9x/ME version?). So also the clock int gets processed too late.

Rutger

Re: PC Losing Time

Venet5-Jul-02 4:17

Venet

5-Jul-02 4:17

If Win2k flavour try to run your application under user permissions rather than using Administrator account and you'll know that you'll get Access Denied if your program tries to change date/time.

Regards,
Venet.

--------
Black holes are where God divided by zero.(Steven Wright)

Re: PC Losing Time

Roger Wright5-Jul-02 4:38

Roger Wright

5-Jul-02 4:38

Alison Pentland wrote:
Surely the time is generated from an RTC (Real Time Clock) chip on the motherboard

The RTC is only read on startup - Windows maintains its own system time from then on. If you're running your code in a fairly tight loop, with constant access to the serial ports, console, and hdd, it may be missing a number of clock update cycles. I've read elsewhere that the clock maintenance process isn't a real high priority, and can be easily bumped by user processes.

Try putting the serial I/O in a separate thread, if it isn't already. I haven't worked a great deal with serial I/O in a long time, but in researching an aborted project that would have needed it, I stumbled across a couple of articles that recommend this as a way to prevent blocking other processes.

There are three types of people in the world: Those who make things happen; those who watch things happen; those who wonder what happened.

Cannot compile .h file?

ivex4-Jul-02 20:56

ivex

4-Jul-02 20:56

I am using VC++ and when I press the compile button a msg box appeared and told me that:
Cannot compile the file '...\myheader.h': no compile tool is associated with the file extension.
Why would this happend?

Re: Cannot compile .h file?

Christian Graus4-Jul-02 22:16

Christian Graus

4-Jul-02 22:16

Because you cannot compile a header file - you need to build the project.

Christian

I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002

Re: Cannot compile .h file?

Alexandru Savescu5-Jul-02 2:14

Alexandru Savescu

5-Jul-02 2:14

You cannot compile a header file. Try compiling the corresponding .cpp file. If there is an error in the header file the compiler will report it.

Best regards,
Alexandru Savescu

Registering OCXs

Jerome Conus4-Jul-02 20:16

Jerome Conus

4-Jul-02 20:16

Hi !

My app is using several OCXs and DLLs. I'm wondering what is the best way to automatically register these OCXs and DLLs. Does InstallShield do it ? Do I have to write my own code calling REGSRV32 serveral times ?

Thank you for your help !
Jerome

Transparent MFC windows with MSVS 6.0

4-Jul-02 19:20

Is there a way to make the MFC windows of my App transparent with MSVS 6.0?
Or is there a downloadable MFC upgrade for WinXP? Or an upgrade for VS 6.0 that supports all new features of WinXP, MFC etc? (without to need to upgrade to VS .NET, at least not yet).
Thank you!

Re: Transparent MFC windows with MSVS 6.0

Christian Graus4-Jul-02 19:57

Christian Graus

4-Jul-02 19:57

You need W2000 or Win XP and you need to download the platform SDK.

Christian

I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002

Re: Transparent MFC windows with MSVS 6.0

5-Jul-02 10:19

Does this SDK contain MFC update and documentation?
I'm not sure about MFC.

Re: Transparent MFC windows with MSVS 6.0

Christian Graus5-Jul-02 17:39

Christian Graus

5-Jul-02 17:39

No it does not. The transparent stuff is done with API calls, which the SDK gives you. How else would your 1995 compiler give you Windows 2000 API calls ?

Christian

I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002

Conversion

4-Jul-02 19:18

hi,
can u tell how to convert a BSTR to LPSTR.

Re: Conversion

Christian Graus4-Jul-02 19:59

Christian Graus

4-Jul-02 19:59

put it through a _bstr_t constructor, it will do it for you. If you construct a _bstr_t and pass in false as a second argument, it will take ownership of the string as well.

_bstr_t b_tEd(bstrEd, false); // No need to clean up the BSTR

anystringfunction(b_tEd); // _bstr_t will do the conversion

It's in comdef.h, I believe.

Christian

I am completely intolerant of stupidity. Stupidity is, of course, anything that doesn't conform to my way of thinking. - Jamie Hale - 29/05/2002

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