C / C++ / MFC Discussion Boards

Grahamfff13-Nov-03 10:12

13-Nov-03 10:12

I need to send data out in two short ints in a message. The source data is in floating representation, range -180.00 to +180.00. This needs to be converted into a scaled 32 bit 2's Complement integer value

So what I need to do is normalise the data;

i.e. float f = 99.9;
f = f/180; // 0.555

Now I need to extract the bits that reprsent the .555 and convert them to a 32 bit bit 2's Complement integer

I was planning to use the union as follows:

union
{
int intValue;
unsigned short buff[2];
}convert;

So once I have converted the float to int I can assign the buff[]

e.g. convert.intValue = floatToInt(f/180);

So now I can load the message using convert.buff[0] and convert.buff[1]

Note I need to check the conversion, so I am planning to do the following:

float f_out = (float) ((buf[0] << 16 | buf[1])*180);

Question how to I convert the float to int?

grahamfff

Re: Scaled float to int conversion

Tim Smith13-Nov-03 10:56

Tim Smith

13-Nov-03 10:56

int i = int ((f/180.0f)*float(MAX_INT));

I don't remember exactly what MAX_INT is called. But it is in limits.h.

float f = float (i) / float (MAX_INT) * 180.0f;

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Win32 service problem. Please help

pankajdaga13-Nov-03 10:01

pankajdaga

13-Nov-03 10:01

Hi everyone,

I am writing a win32 service that listens on a socket. When I run the application in a normal console window, it works fine. However, I cannot initialize the socket when I run it as a service. I found out that the following line was needed:

AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0);

However, this line does not work when I run the service. Coz I guess there is no WinAPP object. But the CSocket object does not initialize and the sevice dies.

Anyone has any ideas how I can init MFC sockets in a service. This is really urgent. I would really appreciate any help.

Thanks,

Pankaj

Without struggle, there is no progress

Re: Win32 service problem. Please help

Antti Keskinen13-Nov-03 10:32

Antti Keskinen

13-Nov-03 10:32

For an easy way out, first read Xiangyang Liu's article Start Your Windows Programs From An NT Service[^]

This article presents you with a service, which is able to start programs before users log on and keep them running after users log off. This way, you don't need to ponder about how to implement MFC to a Win32 service. You can just write a full-fledged MFC application using the MFC App Wizard, and let the XYNTService worry about the rest.

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

Re: Win32 service problem. Please help

pankajdaga13-Nov-03 23:48

pankajdaga

13-Nov-03 23:48

Yeah,

I think I will go for that solution. Thank you so much for pointing that out to me.

Pankaj

Without struggle, there is no progress

XML reply from router?

Kuniva13-Nov-03 9:17

Kuniva

13-Nov-03 9:17

Recently i did a packet capture on my network of what was being sent when i logged into my router and viewed the status page that has the current ip for my router (the ip for the internet side). To my surprise i saw a packet of the http connection that had some XML data in it, like the external ip-address for one. But then when i pressed refresh in IE, or i closed and relogged into my router it didnt send that XML data anymore. Now my question would be why is this? And is there any way i can surely get this XML reply from my router when i connect to it manually? (I don't know much about XML)

Thank you for any assistance.

Kuniva
--------------------------------------------

FlatScrollBar

Tzunga Ma13-Nov-03 9:08

Tzunga Ma

13-Nov-03 9:08

I desperately need help on setting up and using the FlatSB with C, no MFC.
I, by all means know nothing about C++ (btw, sorry if i posted this here), and I just migrated from VB.

I found some samples, like JonathanLivingstone's sample (http://www.codeproject.com/dialog/ScrollableChildDialog/ScrollableChildDialog_demo.zip) which is exactly i wanted.

I need to scroll (with FlatSB) my dialog which has about 50 editboxes & labels.
I know how to do this with VB. I just need to use canvas to group all of these controls, and then scroll it.
But I don't know how to do these with win32 API & C.
Please help me! Eek! | :eek:

I really appreciate any help regarding this.

Output file

Anonymous13-Nov-03 8:13

Anonymous

13-Nov-03 8:13

In my program I have 2 file:input and output.
When I open the first file I am reading the lines where
I have my specific string, other lines I am skiping.
In my output file I need to write my lines with tab delimeter.
How do I do this?

Re: Output file

David Crow13-Nov-03 9:00

David Crow

13-Nov-03 9:00

What are you using to read with: FILE*, istream, CFile, etc?

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: Output file

Anonymous13-Nov-03 9:05

Anonymous

13-Nov-03 9:05

I am using istream.

Re: Output file

David Crow13-Nov-03 9:10

David Crow

13-Nov-03 9:10

Then use ostream::write() to write the data to an output stream (e.g., file).

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

StretchDIBits problem with 16-bit (65536) color

tchu13-Nov-03 7:31

tchu

13-Nov-03 7:31

hello all,

my name is durval and i've the following problem in my project:
when the color-palette from the windows-desktop (properties)
16-bit (65536) is set. on ms-c++ print-preview (mfc) the
::StretchBlt(...)/::StretchDIBits(...)/::::BitBlt(...)
doesn't work properly. the bitmap is dividing in 2 parts, the
right (1/3 from the bitmap) will be put on the left place and
the left is displaced to the right.
at all the other color-settings there's no problem: 8-bit, 24-bit...

do you know this problem?
please, if everybody could help me, it would be very nice.

thanx a lot,
durval.
Frown | :(

the code:

BOOL CDib::Draw(CDC* pDC, CPoint origin, CSize size)
{
if(m_lpBMIH == NULL) return FALSE;
if(m_hPalette != NULL)
::SelectPalette(pDC->GetSafeHdc(), m_hPalette, TRUE);
pDC->SetStretchBltMode(COLORONCOLOR);

// ::BitBlt( pDC->GetSafeHdc(), origin.x, origin.y, m_lpBMIH->biWidth, m_lpBMIH->biHeight, memDC.m_hDC, 0, 0, SRCCOPY );

// ::StretchBlt( pDC->GetSafeHdc(), origin.x, origin.y, size.cx, size.cy, memDC.m_hDC, 0, 0, m_lpBMIH->biWidth, m_lpBMIH->biHeight , SRCCOPY );

::StretchDIBits(pDC->GetSafeHdc(), origin.x, origin.y, size.cx, size.cy,
0, 0, m_lpBMIH->biWidth, m_lpBMIH->biHeight,
m_lpImage, (LPBITMAPINFO) m_lpBMIH, DIB_RGB_COLORS, SRCCOPY);
return TRUE;
}

-------------------------------------------------------------------

system:

Microsoft (R) Windows NT (TM) Workstation
Version 4.0 (Build 1381: Service Pack 6) x86 Uniprocessor Free

-------------------------------------------------------------------

graphic:

BIOS-Datum: 11/17/20
BIOS-Version: Video memory: 1 MB Device Revision: 2.0
Hardware Version 0.0
Adapter:
Setting: 1280 x 1024 x 65536 75 Hz
Typ: i81xnt4-kompatible Grafikkarte
Description: Intel815 Video Accelerator
Memory: 4 MB
Chip-Typ: Intel815
DAC-Typ: Internal
Driver:
Company: <n a="">
Datei(en): i81xnt4.sys, i81xdnt4.dll
Version: <n a="">, 4.0.32

81386745

Float Roading.

Mike Doner13-Nov-03 7:08

Mike Doner

13-Nov-03 7:08

Hi Guys,

I'm having a heck of a time doing some rounding here, hoping someone has a quick solution.

Example:

CHAR string[xx] = "1.019", null terminated string holding the current release.
FLOAT instver, intended to hold the float value of string ( I want it to be 1.019 )

When I do:

sscanf ( string, "%5lf", &instver );

My result is always: 1.0189999

I've tried:

instver = atof ( string );

And I still get the same results. I've done some peeking around the helpfile, can't find anything that will let me truncate/round the decimal spots.

Anybody?
Thx.
Mike.

Re: Float Roading.

JWood13-Nov-03 8:42

JWood

13-Nov-03 8:42

You are always going to get this degradation of floating point accuracy. You need to read up on how floats are stored in IEEE 754 specification.

Floats are stored as a binary value that is composed of the mantissa and the exponent just like in regular scientific notation, however they are binary, so you are converting a decimal format into binary - this is going to cause round-off error.

It is still basicly fairly accurate. If it is just a cosmetic thing you can use format statements and they will round to the correct value for you. printf("%.3f", val); will do this.

J.
----------------------------

Merge sort

Azury13-Nov-03 6:53

Azury

13-Nov-03 6:53

I'm trying to find "Exact Analysis of Merge sort"- M.Golin & R.Sedgewich - Fourth SIAM Conference on Discrete Mathmatics for my assignment. Could you show me where to find it or if you got it, please send to my email
azury_thanh@yahoo.com
Thank you so much Cool | :cool:

Study is suffering!! Unsure | :~

Re: Merge sort

Dhakad13-Nov-03 20:16

Dhakad

13-Nov-03 20:16

merge sort can be implemented in various ways but a very good way to do it is to use the Divide and Conquer Algo.

it divides the array into two.. then sorst the two seperately and then finally merge them back to get the final sorted one.
we use recursive divide calls to divide the array till we get the array with 2 or 1 element.

it runs in time O(n ln n)
if u need the code and the detailed analysis how to derive the complexity.. then mail me.
hope this satisfies u

Deepesh Dhakad
Indian Institute of Information Technology,Allahabad
India

show fields from a table on a Listbox Control using MFC VC++

swerajan13-Nov-03 5:32

swerajan

13-Nov-03 5:32

I have created a lsitbox control, and got a database into MFC application. i am trying to display data from a particular field into the listbox.when i did this
CListBox* pListBox = static_cast<clistbox*> (GetDlgItem(IDC_COURSE));
pListBox->AddString(m_pSet->m_Course);
it is only showing the first one. how can i make display all, and let me choose from it.please let me know

Re: show fields from a table on a Listbox Control using MFC VC++

David Crow13-Nov-03 9:04

David Crow

13-Nov-03 9:04

swerajan wrote:
pListBox->AddString(m_pSet->m_Course);
it is only showing the first one. how can i make display all,

How about a loop?

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Re: show fields from a table on a Listbox Control using MFC VC++

valikac13-Nov-03 9:07

valikac

13-Nov-03 9:07

One solution is InsertItem().

Kuphryn

Re: show fields from a table on a Listbox Control using MFC VC++

David Crow13-Nov-03 9:12

David Crow

13-Nov-03 9:12

Which would be for a list control, would it not?

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

LPCOLESTR

act_x13-Nov-03 5:24

act_x

13-Nov-03 5:24

how to convert LPCOLESTR to CString and viceversa ?

Re: LPCOLESTR

Michael Dunn13-Nov-03 8:08

Michael Dunn

13-Nov-03 8:08

See The Complete Guide to C++ Strings, Part II - String Wrapper Classes[^]

--Mike--
Ericahist | CP SearchBar v2.0.2 | Homepage | RightClick-Encrypt | 1ClickPicGrabber
Pinky, are you pondering what I'm pondering?
I think so Brain, but if we shaved our heads, we'd look like weasels!

thread exit with code 13

avallet13-Nov-03 4:30

avallet

13-Nov-03 4:30

Hi!
I have a dialog based project.
The first dialog is the login, the second the menu.
When I exit from the login (cancel), my thread exits with code 0.
But when I exit from the menu, I close my menu dialog with cancel, and automaticaly my login dialog with CDialog::OnOK(), and the thread exits with code 13.
I don't know where is my bug...
Thanks

Re: thread exit with code 13

Michael Dunn13-Nov-03 8:09

Michael Dunn

13-Nov-03 8:09

Thread exit codes can be whatever you want. The fact that it's non-zero doesn't necessarily indicate an error, and in fact the return code of the main thread of a GUI app is generally not useful.

--Mike--
Ericahist | CP SearchBar v2.0.2 | Homepage | RightClick-Encrypt | 1ClickPicGrabber
"That probably would've sounded more commanding if I wasn't wearing my yummy sushi pajamas."
-- Buffy

WM_CTRLCOLOR

Alton Williams13-Nov-03 3:51

Alton Williams

13-Nov-03 3:51

Hi,
I've subclassed a an edit control from CEdit.
below is what's in the header file:

class CMyEdit: public CEdit<br />
{<br />
public:<br />
void ChangeColour(const unsigned long &bg, const unsigned long &fg);<br />
	// Generated message map functions<br />
protected:<br />
	//{{AFX_MSG(CEditEx)<br />
	afx_msg HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);<br />
	//}}AFX_MSG<br />
<br />
	DECLARE_MESSAGE_MAP()<br />
private:<br />
	CBrush m_brush;<br />
	unsigned long TextColour;<br />
	unsigned long BKColour;<br />
	CFont m_TextFont;<br />
};<br />
<br />
}<br />

the methods in my C++ files are:

HBRUSH CMyEdit::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor) <br />
{<br />
	HBRUSH hbr = CEdit::OnCtlColor(pDC, pWnd, nCtlColor);<br />
	<br />
	// TODO: Change any attributes of the DC here<br />
	pDC->SetTextColor(TextColour);<br />
	<br />
	// TODO: Return a different brush if the default is not desired<br />
	return m_brush;<br />
}<br />
<br />

void CMyEdit::ChangeColour(const unsigned long &fg, const unsigned long &bg)<br />
{<br />
	TextColour = fg;<br />
	BKColour = bg;<br />
	m_brush.DeleteObject();<br />
	m_brush.CreateSolidBrush(BKColour);<br />
	Invalidate();<br />

My problem is why the method OnCtlColor is NOT being called?
Any explanations

Thanks, Alton

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