C / C++ / MFC Discussion Boards

Shankar Chandra Bose17-May-01 14:35

17-May-01 14:35

I've been trying to use std::wifstream to read a unicode file, like so (in a project with UNICODE on):

std::wifstream wf;
wchar_t wch;
wf.open("unicode.txt");

while(wf.get(wch))
{
std::wcout << wch;
}
wf.close();

Funny thing is, this *still* reads the file byte by byte, NOT wchar_t by wchar_t. This means that if you had a 000D in the file, you'd get a 00 followed by a 0D, NOT a 0D as you'd expect. On the other hand, using the C style FILE* does work properly, as:

FILE* fp = _wfopen(L"unicode.txt", L"r+b");
wchar_t wch;
while(!feof(fp))
{
wch = fgetwc(fp);
std::wcout << wch;
}
fcloseall();

The above code accomplishes what I want. However, as I am not too keen on using just C or Win32 functions, can someone shed somelight on what's going on?

Thanks in advance,

Shanker.

Re: Unicode File I/O

l a u r e n18-May-01 12:53

l a u r e n

18-May-01 12:53

i always use the CreatFile() ... ReadFile() ... stuff to read the file in as raw data and then convert to unicode (cast a pointer to it as a _TCHAR*)

works for me Smile | :)

---
"every year we invent better idiot proof systems and every year they invent better idiots"

CRecordset and SQL Server 2000

SuperGeek17-May-01 11:15

SuperGeek

17-May-01 11:15

Hey everyone!!!
I've been getting VERY STUPID DB exception raised by ODBC driver while trying to call CRecordset::Open(....) function.
The message says "Restricted data type attribute violation". Note that my data layer is SQL Server 2000.

If there is a POOR one who has suffered thru the same, please share your grief with me.

Big thanks ahead.
Kirill.

Re: CRecordset and SQL Server 2000

4-Sep-01 1:27

I've had the same error using SQL Server V7.0. It turned out that the order of the DoFieldExchange() member function of the recordset derived from CRecordset have to be in the same order as the table definition.

CFormView Throwing Exception

Christopher17-May-01 10:45

Christopher

17-May-01 10:45

I am writing a program that has two windows in it (splitter). I want both sides to run a dialog. I have created the one for the right side, but when I try and run it I get a debug assertion error. Here is the code I am using:
In CMainFrame:

BOOL CMainFrame::OnCreateClient(LPCREATESTRUCT lpcs, CCreateContext* pContext)
{

if (!m_wndSplitter.CreateStatic(this, 1, 2, WS_CHILD) )
{
AfxMessageBox("Error Creating Splitter Window. [CSplitter::CreatStatic]", MB_OK);
AfxAbort();
//Failed To Create Splitter Window
}

SIZE wndSize;
wndSize.cx=300;
wndSize.cy=600;

if ( (!m_wndSplitter.CreateView(0,0, RUNTIME_CLASS(CTestView), wndSize, pContext)) ||
(!m_wndSplitter.CreateView(0,1, RUNTIME_CLASS(CTagDlg), wndSize, pContext)) )
{
AfxMessageBox("Error Creating Splitter Views. [CSplitter::CreateView]", MB_OK);
AfxAbort();
//Check both views
}

return TRUE;
}
The error seems to come from viewform.cpp, in CFormView::Create it call this function:

if (!_AfxCheckDialogTemplate(m_lpszTemplateName, TRUE))
{
ASSERT(FALSE); // invalid dialog template name
PostNcDestroy(); // cleanup if Create fails too soon
return FALSE;
}

And that is what is throwing the exception. Anyone know how I can fix this?

Ejecting a CD

17-May-01 8:53

I have looked and looked, but I can't find any code to eject a CD-ROM drive in Windows (9x or 2000). I have found a few programs that can do it, but I really need to implement the code inside my project myself. I noticed that the Windows Media Player SDK has some functionality that will do that, but I do not want to be dependent on those libraries to do this. Does anyone have some simple code to do this?

Thanks!

Re: Ejecting a CD

Ed Dixon17-May-01 9:21

Ed Dixon

17-May-01 9:21

DeviceIoControl can be used to do this.

Ed

Re: Ejecting a CD

Tomasz Sowinski17-May-01 9:28

Tomasz Sowinski

17-May-01 9:28

This was tested on Win2000 and WinNT. mciSendString is available on all 32-bit Windows versions, so you should have no problems on Win9X.

char buf[256];
// assume that f: is CD-ROM drive 
// you can use any identifier instead of 'myAlias'
mciSendString("open f: type cdaudio alias myAlias", buf, sizeof(buf), NULL); 
// to eject
mciSendString("set myAlias door open", buf, sizeof(buf), NULL);
// to close CD-ROM door
mciSendString("set myAlias door closed", buf, sizeof(buf), NULL);

Tomasz Sowinski -- http://www.shooltz.com.pl

Re: Ejecting a CD

17-May-01 18:11

Works great (though for SOME reason I was getting really weird errors in the Mmsystem.h, had to redefine UINT, then it was missing Winmm.lib). One question: is there a way to do this without waiting? IE: The program sends the message to close the CD then quits immediately. Right now, as is, it waits for the drive to fully close, and read info about the CD before the last mciSendString executes.

Re: Ejecting a CD

Anders Molin17-May-01 23:54

Anders Molin

17-May-01 23:54

If it's because you want your program to go on with it's business, instead of waiting, just do the open/close stuff in another thread...

- Anders

Money talks, but all mine ever says is "Goodbye!"

Re: Ejecting a CD

18-May-01 4:01

Sure, I figured that was the easiest way to do it, I was just curious to know if there was a way to do it without waiting without relying on a separate thread. I will be opening and closing the drive several times during execution, but at the end of execution it ejects the CD for the user to remove and then quits. I would like to to eject, request that the user remove the CD, and then close the drive, but not wait for the drive after closing. Using a separate thread would still keep the program alive.

Re: Ejecting a CD

Carlos Antollini17-May-01 9:49

Carlos Antollini

17-May-01 9:49

You have the mciSendCommand function.
With this function you can send command messages to MCI devices.

Carlos Antollini.

How to make an output file in VC++

mr200317-May-01 8:49

mr2003

17-May-01 8:49

Hi I have a function in my CView class, it takes a point, and returns the pixel intensity
when I compile it, there's no problem with it,, but there's no output file...
Can anyone help me out????

COLORREF CTestEdgeView::GetPoints( )
{
//this is the class which detects the firt point on the boarder

CClientDC dc(this);
test = dc.GetPixel(m_ptCenter.x +1 , m_ptCenter.y);

ofstream outfile ("ftest.out");
outfile <<"the intensity is: "<< test;

outfile.is_open();
return test;
}

Thanks

Ehsan Behboudi

Re: How to make an output file in VC++

Ravi Bhavnani17-May-01 10:08

Ravi Bhavnani

17-May-01 10:08

Assuming the code works OK, I suspect "ftest.out" is being generated in the default directory (whatever that may be at run time). You might want to retry using a fully qualified filespec like "C:\\ftest.out".

/ravi

"There is always one more bug..."
http://www.ravib.com
ravib@ravib.com

Dynamic creation of objects

Luis Barreira17-May-01 7:57

Luis Barreira

17-May-01 7:57

Is it possible to build a string with a class name and then create a C++ object of that type using some kind of rtti?

Re: Dynamic creation of objects

C^hris L^osinger17-May-01 8:11

C^hris L^osinger

17-May-01 8:11

like this?

CBaseClass *pObj = NULL;

file.ReadString(className);

if (className == ClassA::SerializationName)
pObj = new ClassA;
else if (className == ClassB::SerializationName)
pObj = new ClassB;

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

Re: Dynamic creation of objects

MikeG18-May-01 3:12

MikeG

18-May-01 3:12

Make your objects COM objects. This way you can look them up based on the ProgID.

CLSIDFromProgID( L"ClassName", &clsid );
hr = CoCreateInstance( clsid, NULL, CLSCTX_ALL,
__uuidof(IClass), (void **) &pIClass );

This has the benefit of not needing to do some big if statement and adding a new string every time a new class is added.
Mike

Re: Dynamic creation of objects

Tomasz Sowinski18-May-01 3:21

Tomasz Sowinski

18-May-01 3:21

You can pick some ideas from this article by Allen Holub:
http://msdn.microsoft.com/library/periodic/period96/S385.htm

Tomasz Sowinski -- http://www.shooltz.com.pl

Dial-In Authentication by RADIUS NT/2000

17-May-01 7:44

Hi, I'm searchig for a routine for Authenticating users that dial to a NT4/2000 server, using RADIUS protocol, because users passe through a router that server is connected to it.

Please help me. Confused | :confused:

Regards,
HAMED.

Memory error closing if use function that are in DLL

17-May-01 7:41

Hello!
The fact: I created a program with mfc the access an .mdb database through a Regular MFC DLL
statically linked (i must do that). I add th DLL to my core program, i execute all the function,
like insertion of record, etc through the dialogs in DLL and the db in the DLL.
When i close the app i always get an error cause "the memory could not be read". All works fine
but this message box.
This, only when i use CDaoRecordset (that i must use instead of CRecordset), cause when i call a
function that show ie a message box, the memory error dont appear.. sigh
Anyone has an idea on how to kill this problem?

Re: Memory error closing if use function that are in DLL

Dark Angel17-May-01 16:09

Dark Angel

17-May-01 16:09

Have you tried rebuilding the entire project? ( i.e. Clean / Rebuild all )

If putting a MessageBox in will make the problem go away, then it is quite likely that the program's stack is corrupted. You also need to make sure that the .lib file you are statically linking with is up to date. i.e. build the dll first, then use the up to date .lib file to build the executable. The joys of statically linking.
Roll eyes | :rolleyes:

"Harland Pepper, would you stop naming nuts" - Harland Pepper

Logon Domain and Userid

Chris Meech17-May-01 5:59

Chris Meech

17-May-01 5:59

I have a need to build a string as follows; "DOMAINNAME\USERID". In looking through the MSDN docs on networking it appears that I can use the API function NetWkstaUserGetInfo(). The docs say you have to include the header lmwksta.h. When you do this and compile, that header causes a compile error and inside it's documentation it says you must include netcons.h before you include this file. Unfortunately that file, netcons.h, does not exist on my PC anywhere. Mad | :mad:

I've tried searching for variations on the name but have still come up empty. Does anyone have a thought on what might be broken? Or another way for me to put this particular string together. Thanks.

Chris

Re: Logon Domain and Userid

Carlos Antollini17-May-01 6:21

Carlos Antollini

17-May-01 6:21

You only need the header lm.h and do not forget to link with the Netapi32.lib library.
Cheers!!!

Carlos Antollini.

Re: Logon Domain and Userid

Chris Meech17-May-01 6:43

Chris Meech

17-May-01 6:43

Thanks Carlos. With some more searching I found that there is a header file called lmcons.h. And in this file is a comment that it used to be called .. .. .. ta da. NETCONS.H

But I like your suggestion better. Just include lm.h and I should get all that will need. Thanks again.

Chris

detecting IP

17-May-01 5:54

How to detect the IP of the computer the programm is working on? Big Grin | :-D

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