Re: VS2003 for loop bug? - C / C++ / MFC Discussion Boards

Re: wizard finish button and message box

misha_grewal12-Jun-07 4:54

misha_grewal

12-Jun-07 4:54

Thanks much
it works with this call
i m really stupid

VS2003 for loop bug?

mcsherry12-Jun-07 2:58

mcsherry

12-Jun-07 2:58

In my Visual Studi 2003 C++ project I've got a weird bug. I have a 'normal' for loop:

int i = 0 ;
for ( i = 0 ; i < m_NumberOfObjects ; i++ ) ;
{
  m_ListObjects[i]->DoStuff ( ) ;
}

where m_NumberOfObjects is a static int (member variable) within the class.

The problem is the for loop seems o ignore the entry criteria so if i = 0 and m_NumberOfObjects = 0 is still goes in (even with i = 1 and m_NumberOfObjects replaced with a 0)

Has anyone came across this? or know what is going wrong?

TIA,
Andy

Re: VS2003 for loop bug?

mcsherry12-Jun-07 3:03

mcsherry

12-Jun-07 3:03

doesn't matter I'm an idiot, stray semi-colon D'Oh! | :doh:

Re: VS2003 for loop bug?

Mark Salsbery12-Jun-07 6:59

Mark Salsbery

12-Jun-07 6:59

mcsherry wrote:
stray semi-colon

Don't let 'em get away from you. They're feisty little buggers Smile | :)

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Re: VS2003 for loop bug?

S Douglas12-Jun-07 20:23

S Douglas

12-Jun-07 20:23

Mark Salsbery wrote:
Don't let 'em get away from you. They're feisty little buggers

Re: VS2003 for loop bug?

_AnsHUMAN_ 12-Jun-07 3:05

_AnsHUMAN_

12-Jun-07 3:05

You should not put the ";" after the for loop Dear...
and you don't normally come across such issues if you know how does a for loop work:->

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: VS2003 for loop bug?

CPallini12-Jun-07 3:08

CPallini

12-Jun-07 3:08

The bug is the semicolon ; following the for statement: an empty statement is controlled by the for expression while the code block inside the curly braces {} is always executed.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: VS2003 for loop bug?

Matthew Faithfull12-Jun-07 3:11

Matthew Faithfull

12-Jun-07 3:11

I suspect you're suffering from a change in the syntax between VC6 and Visual Studio 2003 C++ combined with a stray semi colon. The scope of counters in for loops (i in your case ) has changed so that if they're declared in the loop they can't escape from the loop. You possibly have 2 i's happening here in different scopes which is Confused | :confused:

to say the least. I now use this syntax to try and be both 'correct' and compatible

<br />
//'correct' and compatible but wouldn't help you pick up this bug<br />
int i = 0;<br />
for( ; i < m_NumberOfObjects; i++ )//Notice no ; here<br />
{<br />
  m_ListObjects[i]->DoStuff();<br />
}<br />
<br />
//recommended to prevent i leaking from scope but I dont' think you can do this anymore :doh:<br />
for( int i; i < m_NumberOfObjects; i++ )//<br />
{<br />
  m_ListObjects[i]->DoStuff();<br />
}<br />

The extra ; has caused the intended loop code to happen only once and declaring the i outside has let you get away with it Frown | :(

Perhaps that's why they changed it.

Nothing is exactly what it seems but everything with seems can be unpicked.

Re: VS2003 for loop bug?

mcsherry12-Jun-07 3:22

mcsherry

12-Jun-07 3:22

thanks all for your replies, obviously just the stray semi-colon (couldn't spot it after looking at the code for ages, post the question on here and spot it straightaway Sigh | :sigh:

always the same!)

Andy,

Re: VS2003 for loop bug?

BadKarma12-Jun-07 4:21

BadKarma

12-Jun-07 4:21

I know the feeling. Frown | :(

Therefor I sometimes use one of my colleagues to wine about some extreme strange bug.
They are willing to help. Once I show them the piece of code and start explaining what it suppose to do. I start swearing at my own stupidity. Time on time i have found the bug before they do. Laugh | :laugh:

codito ergo sum

Re: VS2003 for loop bug?

vijay_aroli12-Jun-07 3:33

vijay_aroli

12-Jun-07 3:33

mcsherry wrote:

int i = 0 ;
for ( i = 0 ; i < m_NumberOfObjects ; i++ ) ;
{
m_ListObjects[i]->DoStuff ( ) ;
}

there you are. The semi colon in the second line is causing problems to you. Smile | :)

sorry, i didn't see that you figured it out by yourself. D'Oh! | :doh:

Regards,
Vijay.

God may not give us what we 'want', but he surely gives us what we 'need'.

Re: VS2003 for loop bug?

Michael Dunn12-Jun-07 6:21

Michael Dunn

12-Jun-07 6:21

The compiler should have given you a warning about that semicolon. If not, turn warnings back on. Smile | :)

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

LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ

Dunder-Mifflin, this is Pam.

Re: VS2003 for loop bug?

Mark Salsbery12-Jun-07 7:02

Mark Salsbery

12-Jun-07 7:02

I don't think so Mike. That looks like completely valid C code with the semi-colon in there.

That one would drive me nuts if I didn't see it right away in my code LOL

Smile | :)

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

How to detect device Type

VC_RYK12-Jun-07 2:52

VC_RYK

12-Jun-07 2:52

Hi All

i want to detect at run time what kind of device is connected to USB port(like if Digital camera is connected then it shows Digital camera etc.)like how our windows is showing(if you cannect scanner to USB port then in My computer you can view in "Type" Image scanner.
i got something "SystemParametersInfo" but i dont know how will i use it and wheter it is useful or not

Thanks in advance
R e h a n

Re: How to detect device Type

act_x13-Jun-07 6:29

act_x

13-Jun-07 6:29

Basically the symbolic link for the device should have the GUID which should be unique per type .

Look into plug and play notifications on Windows

Engineering is the effort !

Change the color of static control

TobetheWinner12-Jun-07 2:47

TobetheWinner

12-Jun-07 2:47

I want to change the color of static control to white.As well as in the static controls the text also should be visible.

CStatic temp = new CStatic();
temp->Create(text ,style |SS_LEFT ,pos ,this ,m_iAutoControlID);

bhw

Re: Change the color of static control

Hamid_RT12-Jun-07 3:13

Hamid_RT

12-Jun-07 3:13

See WM_CTLCOLORSTATIC and on the this message use of SetTextColor() for text color and SetBKColor() for background color.

WhiteSky

Change the color of static control

TobetheWinner12-Jun-07 3:50

TobetheWinner

12-Jun-07 3:50

This is a dynamically created control.is there any style or method to do that.

bhw

Re: Change the color of static control

Hamid_RT12-Jun-07 4:00

Hamid_RT

12-Jun-07 4:00

I dont understand what you said can you more explain.

WhiteSky

Re: Change the color of static control

David Crow12-Jun-07 4:15

David Crow

12-Jun-07 4:15

WhiteSky wrote:
I dont understand what you said can you more explain.

The control is created at runtime rather than design time.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Change the color of static control

Hamid_RT12-Jun-07 4:22

Hamid_RT

12-Jun-07 4:22

No I want to know his question was about control or color.

WhiteSky

Re: Change the color of static control

Max Santos12-Jun-07 6:28

Max Santos

12-Jun-07 6:28

Hello

Use WinProc or PreTranslateMessage to catch the message WM_CTLCOLORSTATIC
and compare the control id with the id that you give to your static.

And then is just the same as if you use the designer.

Something like this:

BOOL CYourDialog::PreTranslateMessage(MSG* pMsg) <br />
{<br />
	if(pMsg->message == WM_KEYDOWN && pMsg->wParam==VK_RETURN)<br />
	{<br />
		if(IsWindow(m_YourStatic.m_hWnd))<br />
		{<br />
			if(pMsg->hwnd==m_YourStatic.m_hWnd)<br />
			{<br />
				DoSomething();<br />
			}<br />
		}<br />
	}<br />
}

http://xwega.com

Stop Closing the main Dialog when a child Dailog is open? [modified]

granshah @ eVisionISF12-Jun-07 2:40

granshah @ eVisionISF

12-Jun-07 2:40

I am new to window programming and I need to do a task which is to know whether all the child dialogs have been exited before closing the main dialog. Can you please direct me, how can i do it?

Further explanation is the main dialog should not exit of ESC key unless all the child dialogs are properly closed.

Thanks in advance.

S.S

-- modified at 8:53 Tuesday 12th June, 2007

Re: Need to know a method?

David Crow12-Jun-07 2:41

David Crow

12-Jun-07 2:41

Are the child dialogs modal or modeless?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Need to know a method?

Mark Salsbery12-Jun-07 7:08

Mark Salsbery

12-Jun-07 7:08

DavidCrow wrote:
Are the child dialogs modal

I hope not Smile | :)

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

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