Re: Arithmetic Expression - C / C++ / MFC Discussion Boards

Jon Hulatt20-Jan-02 21:52

20-Jan-02 21:52

Why would you want to? compilation of file order is irrelevant!?!

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Re: File Compiling Order in VC++

Aaron K.B. Huang20-Jan-02 21:58

Aaron K.B. Huang

20-Jan-02 21:58

The order maybe bases on your head files' order.;P

CProgressCtrl

RobJones20-Jan-02 18:13

RobJones

20-Jan-02 18:13

Hello,
I have a MDI app. and in the status bar I have a progress control.. The problem I am having is when ever a long function is taking place my app freezes until the function is finished (because of the progress control). If I remove the progress control everything is fast and smooth.. How can I create a progress control in the status bar with out killing my application performance? Here is a sample of the code I use to create the progress control.

void CMainFrame::DownloadProgress(long nProgress, long nProgressMax)
{
	RECT MyRect;
	m_wndStatusBar.GetItemRect(1, &MyRect);  

	if (m_bCreate == FALSE)
	{
		//Create the progress control
		m_Progress.Create(PBS_SMOOTH | WS_VISIBLE | WS_CHILD 
			, MyRect, &m_wndStatusBar , 1);
		
		m_Progress.SetRange(nProgress,nProgressMax); //Set the range
 		m_Progress.SetStep(1); // Set the step amount
		m_bCreate = TRUE;
	}

	for (int i = nProgress; i < nProgressMax; i++)
	{
			m_Progress.StepIt(); 
	}

}

Any pointers?

Thanks,
Rob

Re: CProgressCtrl

Michael Dunn20-Jan-02 19:00

Michael Dunn

20-Jan-02 19:00

It sounds like you're doing everything in one thread, no? If so, read the VC forum FAQ (link at the top of the page) that addresses your question.

--Mike--
"Why you keep calling me Jesús? I look Puerto Rican to you?"
-- Samuel L. Jackson in Die Hard 3
My really out-of-date homepage
Sonork - 100.10414 AcidHelm
Big fan of Alyson Hannigan.

Re: CProgressCtrl

RobJones20-Jan-02 19:23

RobJones

20-Jan-02 19:23

You were correct, I am in a single thread.. Thanks for the post, everything works great. Smile | :)

Rob

Arithmetic Expression

Geoffrey20-Jan-02 17:36

Geoffrey

20-Jan-02 17:36

Could anyone help me with the following expressions?

n5-=7+2/3*10

and also

f2=10.0-18.0/-3.0*2.5e-1

Geoffrey A Overley

Re: Arithmetic Expression

Jon Sagara20-Jan-02 18:03

Jon Sagara

20-Jan-02 18:03

Did you try writing a small program to see what results you would get?

Jon Sagara

What about ?

Re: Arithmetic Expression

Jon Hulatt20-Jan-02 21:58

Jon Hulatt

20-Jan-02 21:58

ok. saying "n5 -=" is equivalent to saying "n5=n5-". the rest of it is down to operator precedence. see "operator presecence" in MSDN.

but, you can make that expression clearer by writing it like this:

n5=n5- 7 + (2 / (3 *10)) ;

why? because in VC++, / has higher precedence that +

the second expression:

f2= 10.0 - (18.0 / (-3.0 * 2.5e-1));

In both cases, i suspect you're getting a different answer than you intended, due to operator precedence. It's good practise to always specify precedence with ()'s.

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Re: Arithmetic Expression

Christian Graus20-Jan-02 22:08

Christian Graus

20-Jan-02 22:08

Jon Hulatt wrote:
n5=n5- 7 + (2 / (3 *10)) ;

This is wrong. It evaluates as I said in the lounge - 2 gets divided by 3 and the result multiplied by 10, so that part comes to zero ( because 2 and 3 are not floats ), but if it gets made 2.0 and 3.0, you get 6.666(10 * .66666), not 0.0666 (2/30). / and * have equal precedence, left to right.

So the correct way to use brackets to show order of operation is

7 + ((2/3)*10)

and the 2 and 3 should be floats in order to get an answer other than 7.

Also, are you recommending not using -= here, or am I misreading you ?

Jon Hulatt wrote:
f2= 10.0 - (18.0 / (-3.0 * 2.5e-1));

Again, this is wrong - put it into a console application and see for yourself. The result is 11.5, not 34 as your bracketing would evaluate to.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Re: Arithmetic Expression

Jon Hulatt21-Jan-02 1:54

Jon Hulatt

21-Jan-02 1:54

That'll teach me to read the doc's more carefully. I forgot that * and / had equal precedence, in left-to-right order.

I wasn't recommending not using -= at all. from the guys original post it wasn't clear exactly what he was having trouble with.

Anyway, my incorrect answer to the question highlights why it's a good idea to always enforce your own precedence using ()'s. Especially if you use different languages frequently where precedence varies.

Smile | :)

Sorry to dissapoint you all with my lack of a witty or poignant signature.

Re: Arithmetic Expression

Christian Graus21-Jan-02 5:45

Christian Graus

21-Jan-02 5:45

Jon Hulatt wrote:
Anyway, my incorrect answer to the question highlights why it's a good idea to always enforce your own precedence using ()'s. Especially if you use different languages frequently where precedence varies.

Absolutely - I use a lot of brackets especially in the case mentioned, where a multiply happens after a divide. It's always better to have brackets show what you assume will happen, just in case your assumption is wrong.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Arithmetic

Geoffrey20-Jan-02 17:36

Geoffrey

20-Jan-02 17:36

Could anyone help me with the following expressions?

n5-=7+2/3*10

and also

f2=10.0-18.0/-3.0*2.5e-1

Geoffrey A Overley

Re: Arithmetic

Christian Graus20-Jan-02 17:47

Christian Graus

20-Jan-02 17:47

Geoffrey, while this question is probably better off here than in the lounge, it was general enough that I answered it there. Either way, please don't ask the same questions over and over, once here is enough.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

Best wat to download a file with http?

Jay Beckert20-Jan-02 16:35

Jay Beckert

20-Jan-02 16:35

What is the best way to download a file with http protocol and actually test to see if that file really does exist? I have looked and looked to no avail. Any help will be greatly appreciated. Smile | :)

Bill? Who's this guy called Bill?

Re: Best wat to download a file with http?

Michael Dunn20-Jan-02 16:55

Michael Dunn

20-Jan-02 16:55

Use URLDownloadToFile().

--Mike--
"Why you keep calling me Jesús? I look Puerto Rican to you?"
-- Samuel L. Jackson in Die Hard 3
My really out-of-date homepage
Sonork - 100.10414 AcidHelm
Big fan of Alyson Hannigan.

Re: Best wat to download a file with http?

Jay Beckert20-Jan-02 16:59

Jay Beckert

20-Jan-02 16:59

lol Why is it always the obvious things we overlook?
I used OpenURL() but no real way of checking if it exist or not; Unless I make it a complicated task.

Thanks Mike Smile | :)

CopyMemory problems

alex.barylski20-Jan-02 12:59

alex.barylski

20-Jan-02 12:59

Can some one tell me what the problems is...?

LPCTSTR GetBuffer()
{
LPSTR buff = "";
CopyMemory(buff, GlobalLock(m_hBuffer), m_nSize);
GlobalUnlock(m_hBuffer);
return buff;
}

CopyMemory fails!!! I've managed to use similar code for the SetBuffer function.

CopyMemory(GlobalLock(m_hBuffer), buff, m_nSize);

Why does the one work and not the other...?

TIA Confused | :confused:

"An expert is someone who has made all the mistakes in thier field" - Niels Bohr

Re: CopyMemory problems

alex.barylski20-Jan-02 13:28

alex.barylski

20-Jan-02 13:28

I've fixed the problem, but i dunno if it's a proper fix.

LPCTSTR buff = (LPCTSTR)GlobalLock(m_hBuffer);
GlobalUnlock(m_hBuffer);
return buff;

I'm assuming the prob was that the temp buff is destroyed when outta scope...? So the CopyMemory had no effect. ultimately all i wanted returned was an address to the buffer and the above does this. However Locking the handle returns a pointer, doesn't Unlocking invalidate the handle...?

The above code works, but isn't it set up for failure, i'm kinda lost as to why it does work...? Confused | :confused:

Each Lock increments a counter kinda like COM objects right..? as the Unlock does the opposite, as long as the lock count is zero shouldn't it fail...?

Thanx again!

"An expert is someone who has made all the mistakes in thier field" - Niels Bohr

put images on GDI

DiegoValdevino20-Jan-02 12:54

DiegoValdevino

20-Jan-02 12:54

How can I put a array that represents an image on my window. Have I to create a DC or something? Name of functions and explanations would be very nice.

Re: put images on GDI

Christian Graus20-Jan-02 13:03

Christian Graus

20-Jan-02 13:03

DO you mean an array of pixel values ? You can create a DIBSection and copy the data directly onto the bitmap if you want to. Any decent DIBSection wrapper will also have a draw function, so all you need to do is pass in the DC you get in OnPaint.

Christian

I have come to clean zee pooollll. - Michael Martin Dec 30, 2001

Sonork ID 100.10002:MeanManOzI live in Bob's HungOut now

TopMost Maximized Window?

DiegoValdevino20-Jan-02 12:50

DiegoValdevino

20-Jan-02 12:50

I have just started today with dirctx8 and I want to make a window in full screen mode. The DX SDK says to create a "topmost" window with WS_EX_TOPMOST.
I had my window topmost , but not Maximized.

How can I do it ?

ps: Without window borders!!!

Re: TopMost Maximized Window?

Andrew Peace20-Jan-02 14:39

Andrew Peace

20-Jan-02 14:39

I think you need to look in the SetCooperateLevel function (I think that's the name, anyway, or something like it). Also, it would be good advice to look at the DirectX sample progras, they are a gold mine.

--
Andrew.

create an owned popup window

20-Jan-02 12:18

How does one create an owned popup window?

If I use

CreateEx(NULL,
        AfxRegisterWndClass(CS_HREDRAW | CS_VREDRAW, 0, (HBRUSH)(COLOR_WINDOW + 1), 0),
        NULL,
        WS_POPUP | WS_VISIBLE | WS_BORDER,
        rect,
        pParent,
        1,
        NULL);

CreateEx fails to create a window

but, if I use

CreateEx(NULL,
        AfxRegisterWndClass(CS_HREDRAW | CS_VREDRAW, 0, (HBRUSH)(COLOR_WINDOW + 1), 0),
        NULL,
        WS_CHILD | WS_VISIBLE | WS_BORDER,
        rect,
        pParent,
        1,
        NULL);

CreateEx successfully creates a window, but it's visibility is limited to it's parent's client area.

My class is derived from CWnd, and I call CreateEx() in the constructor.

TIA

TA.

Re: create an owned popup window

24-Jan-02 15:18

Does noone use use CWnd::CreateEx() to create a popup window Confused | :confused:

why would CreateEx() fail when the WS_POPUP flag is used, but if I use the CreateWindowEx() API function, with the exact same parameters as above, the window is successfully created?
I am very confused, and in the 2 days since I posted the original question, I have not gotten an answer. maybe this forum is not as helpful as I have been told Cry | :((

Skin a window

The_Server20-Jan-02 12:12

The_Server

20-Jan-02 12:12

How can I skin a window?

for example: Title, Window client area, Tool Bar, Menues, Fonts, etc.

Every help needed links.

Mad | :mad:

Anything . . . Mad | :mad:

Please HELP ! ! !

A S A P.

Thanks.

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