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Don Box27-Jul-07 23:31

27-Jul-07 23:31

R u talking about changing the color of all rows of list ctrl or few rows?

Come online at:-
jubinc@skype

Michael Dunn28-Jul-07 9:32

28-Jul-07 9:32

Neat Stuff to do in List Controls Using Custom Draw[^]

--Mike--
Visual C++ MVP Cool | :cool:

Cool | :cool:

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Dunder-Mifflin, this is Pam.

Nelek29-Jul-07 22:04

29-Jul-07 22:04

I don't remember the name of the article, but there is one very good CListCtrl here in code project that implements simple row, files, cells changing colors and a lot of additional features. Take a look in the sction MFC controls or search articles CListCtrl-related

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Hamid_RT31-Jul-07 21:07

31-Jul-07 21:07

You can derived CListCtrl and use of cusom message to change color of items and background.

WhiteSky

convert from size_t to unsigned int

George_George27-Jul-07 20:32

27-Jul-07 20:32

Hello everyone,

When converting from size_t to unsigned int, there will be a warning message,

warning C4267: '=' : conversion from 'size_t' to 'int', possible loss of data

I do not know why, since in crtdbg.h, size_t is defined to int, right?

thanks in advance,
George

Re: convert from size_t to unsigned int

Don Box27-Jul-07 20:44

27-Jul-07 20:44

Plzz write the statement u've written in u'r source which is generating the warning.

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jubinc@skype

Re: convert from size_t to unsigned int

George_George27-Jul-07 21:28

27-Jul-07 21:28

Hi Don,

I am using fread to read contents from a file and the return value is size_t. Then I need to pass the size_t value to another function which accepts unsigned int as input parameter, and this is why I need to do the type conversion.

Any suggestions to solve this issue? (which types should I convert to? Any possible lost of data?)

regards,
George

Re: convert from size_t to unsigned int

Eytukan27-Jul-07 22:53

27-Jul-07 22:53

Pragma warning disable! It doesn't hurt when you send a size_t to an int param. You could do like (int)size_tVariableHere, when you pass size_t as an int argument. The "possible loss of data" could be about the sign information. size_t is unsigned, We can be sure size can't be in negative, so you can very well use it. It's not a problem at all.

btw : add this in your header:

pragma warning( disable : C4267 )

He's become a household word in the Lounge. A whole new phraseology has evolved. Post a link or reply with a smiley and rose, and you've made a "Satipsism". So what? It's an interesting thing about the Internet, the evolution (as in change, not progress) of tone, quality, terminology, etc.

-Marc Clifton.

Best wishes to Rexx[^

Re: convert from size_t to unsigned int

George_George27-Jul-07 23:19

27-Jul-07 23:19

Hi VuNic,

I find even if I convert to an unsigned int, the warning message is the same. I am using Visual Studio 2003.

Do you know the reason?

regards,
George

Re: convert from size_t to unsigned int

Don Box27-Jul-07 23:29

27-Jul-07 23:29

I would like to tell that size_t is an unsigned int. If u convert it into int, then it may have loss of data. But as u r saying, u r sending to a function accepting unsigned int, then there should not be any warning like such.
But as u r passing the return value of fread and u won't read more than 2147483647 bytes at a time, it won't have any problem. Let the warning appear.

Come online at:-
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Re: convert from size_t to unsigned int

George_George27-Jul-07 23:54

27-Jul-07 23:54

Thanks Don,

I am using Visual Studio 2003. I think there should not be any warning if I convert size_t to unsigned int, but there actually a warning. Strange.

regards,
George

Re: convert from size_t to unsigned int

John R. Shaw28-Jul-07 0:05

28-Jul-07 0:05

I know this was already answered but you are obviously not trying to covert it to unsigned int.. You are correct that a size_t is an unsigned int, so technically no conversion is needed. You are trying to convert an unsigned int to an it, which could result in a loss of data if the value exceeds 32,768 (3K).

In any case the ‘warning…’ means exactly what it says.

INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra

Re: convert from size_t to unsigned int

George_George28-Jul-07 0:12

28-Jul-07 0:12

Hi John,

I do not know why there will be data lost if I convert size_t to unsigned int. Could you show me an example please?

(I am using 32-bit machine.)

regards,
George

Re: convert from size_t to unsigned int

John R. Shaw28-Jul-07 0:37

28-Jul-07 0:37

You had me worried there for a moment – I thought I did not make it clear. No conversion is needed, the warning says you are converting it to an ‘int’ which will result in possible data loss – if and only if the value exceeds 2,147,483,647 (corrected for 32-bit integer).

The warning is not saying that you have a possible loss of data when converting to ‘unsigned int’, it says you are converting it too ‘int’, which is why the warning is occurring.

INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra

Re: convert from size_t to unsigned int

George_George28-Jul-07 1:25

28-Jul-07 1:25

Hi buddy,

You can try that even if we convert to unsigned int, the warning message is the same in Visual Studio 2003.

Any ideas?

regards,
George

Re: convert from size_t to unsigned int

Eytukan28-Jul-07 3:27

28-Jul-07 3:27

OMG | :OMG:

You are still talking about the warnings? These warnings are meant to be ignored once you know what they are warning about. I've a piece of code that uses STL Map, and when you compile, the compiler takes minutes to stop it's warning process. Where you should only use the pragma-warning-disable.

He's become a household word in the Lounge. A whole new phraseology has evolved. Post a link or reply with a smiley and rose, and you've made a "Satipsism". So what? It's an interesting thing about the Internet, the evolution (as in change, not progress) of tone, quality, terminology, etc.

-Marc Clifton.

Best wishes to Rexx[^

Re: convert from size_t to unsigned int

George_George28-Jul-07 3:36

28-Jul-07 3:36

Thanks VuNic,

Do you think convert from size_t to unsigned int will cause data lost on 32-bit platform?

regards,
George

Re: convert from size_t to unsigned int

Eytukan28-Jul-07 4:05

28-Jul-07 4:05

George_George wrote:
Do you think convert from size_t to unsigned int will cause data lost on 32-bit platform?

You will loose if you send signed number. Ok, test it by yourself :

<br />
	int nIntNeg = -100;<br />
	int nIntPos = 100;<br />
	size_t sz;<br />
	sz=nIntPos;<br />
	cout<<"\n"<<sz;<br />
<br />
	sz=nIntNeg;<br />
	cout<<"\n"<<sz<<endl;<br />

The point here is not about you will/will-not loose data, but it's to say that you wont get into a situation where a function would return signed number for a size_t type.
Eg:

<br />
	std::string st;<br />
	st="";<br />
	cout<<st.size();<br />

At the worst, st's size can me only 0, can't go below that. So you get the point? size_t s are meant for unsigned data. If you send signed numbers, you WILL loose it.

He's become a household word in the Lounge. A whole new phraseology has evolved. Post a link or reply with a smiley and rose, and you've made a "Satipsism". So what? It's an interesting thing about the Internet, the evolution (as in change, not progress) of tone, quality, terminology, etc.

-Marc Clifton.

Best wishes to Rexx[^

Re: convert from size_t to unsigned int

George_George28-Jul-07 19:28

28-Jul-07 19:28

Hi VuNic,

I can understand your points. But I am always using unsigned int. Do you think there will be any data lost if I convert size_t to unsigned int on 32-bit machine?

regards,
George

Re: convert from size_t to unsigned int

Roger Broomfield28-Jul-07 3:03

Roger Broomfield

28-Jul-07 3:03

always look to the latest MSDN for info on compiler warnings http://msdn2.microsoft.com/en-us/library/6kck0s93(VS.80).aspx[^]

Re: convert from size_t to unsigned int

George_George28-Jul-07 3:27

28-Jul-07 3:27

Hi Roger,

I am using 32-bit only (no 64-bit). I have read the URL from MSDN and there may be warnings when we are using 64-bit platform. But I do not know why in my 32-bit environment, there is still the warning message.

regards,
George

Re: convert from size_t to unsigned int

Eytukan28-Jul-07 3:33

28-Jul-07 3:33

pragma warning( disable : C4267 )

Did you do this or not?, put that in the afx.h header.

He's become a household word in the Lounge. A whole new phraseology has evolved. Post a link or reply with a smiley and rose, and you've made a "Satipsism". So what? It's an interesting thing about the Internet, the evolution (as in change, not progress) of tone, quality, terminology, etc.

-Marc Clifton.

Best wishes to Rexx[^

Re: convert from size_t to unsigned int

George_George28-Jul-07 3:38

28-Jul-07 3:38

Hi VuNic,

You mean it is a false warning?

regards,
George

Re: convert from size_t to unsigned int

Eytukan28-Jul-07 4:14

28-Jul-07 4:14

Here[^]
Relatively it's a simple question, wondering it required so much explantion. Think it this way,
Floats are meant for storing percision data, if you store a float value in an int? wont it loose the precision? But you are not going to do that right? the same way unless or otherwise you manually do something like :

<br />
void myFunction(size_t sz)<br />
{<br />
<br />
}<br />

and pass something like
myFunction(-100);
There's no possiblity of loosing data. In short, It looks you aren't sending negative values in your code so please ignore the warning.

He's become a household word in the Lounge. A whole new phraseology has evolved. Post a link or reply with a smiley and rose, and you've made a "Satipsism". So what? It's an interesting thing about the Internet, the evolution (as in change, not progress) of tone, quality, terminology, etc.

-Marc Clifton.

Best wishes to Rexx[^

Re: convert from size_t to unsigned int

George_George28-Jul-07 19:30

28-Jul-07 19:30

Hi VuNic,

I am always using unsigned int as data type. Example,

unsigned int i = <some value="">;
size_t new_value = (size_t)i;

I am not sure whether there will be any data lost if I convert i to new_value as size_t type. I can understand convert to signed int will cause data lost. What about unsigned int?

Looks like we are talking about two different things. Smile | :)

Smile | :)

regards,
George

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