C / C++ / MFC Discussion Boards

nss9-Feb-03 7:58

9-Feb-03 7:58

What am I doing wrong? I want to read the names from a file and put them onto a vector of char*......it crashes at the pushback. Each file name is on a different line.

I did a dir/b in dos and got a txt file with a list of file names (a bunch of .bmps) from the directory. I assume theres carriage returns at the end of each line. But maybe not. There are 18 letters in the name08FEB096_9571s.bmp, and carriage return line feed is 1 byte (MSDN).

CFile file;

std::vector<char*> fileVec;

file.Open("c:\\miss\\SImages.txt", CFile::modeRead, 0);

char* pBuf;

char folder[200];

strcpy(folder , "C:\\miss\\");

for (int i = 0; i <96; i++)
{

    pBuf = new char[200];

    file.Read( pBuf,20);

    strcat(folder, pBuf);

    fileVec.push_back(folder);

    delete[] pBuf;
}


file.Close();

Re: crash with push_back for vector

C^hris L^osinger9-Feb-03 8:50

C^hris L^osinger

9-Feb-03 8:50

looks like the board ate some of your code. how is your vector defined? (what is it a vector of?)

-c

WWT2D?

Fractals

Re: crash with push_back for vector

nss9-Feb-03 13:11

nss

9-Feb-03 13:11

It was avector of CString. However my problem was that I was using CFile when CStdioFile was more suitable and I had overwritten some buffers, but the poor vector got blamed....

Thanks. Smile | :)

Re: crash with push_back for vector

Solomon Wu9-Feb-03 18:17

Solomon Wu

9-Feb-03 18:17

CFile file;
change std::vector fileVec;
to std::vector<string> fileVec;

Move strcpy(folder,"c:\\miss\\");
to For Statement

for (int i = 0; i <96; i++)	{		
    strcpy(folder , "C:\\miss\\");	
    pBuf = new char[200];			
    file.Read( pBuf,20);		
    strcat(folder, pBuf);		
    fileVec.push_back(folder);		
    delete[] pBuf;	
}

Learning and Working

Re: crash with push_back for vector

Jambolo9-Feb-03 21:55

Jambolo

9-Feb-03 21:55

Nobody explained the reason for the crash...Without the unimportant stuff, here is what the code looks like. Do you see the problem?

char folder[200];
strcpy(folder , "C:\\miss\\");
for (int i = 0; i <96; i++)
{
...
strcat(folder, pBuf);
...
}

thanks everyone!!!

ns10-Feb-03 1:15

10-Feb-03 1:15

Yup. I saw finally....my poor "folder" variable was getting concatenated way beyond its allocated space...
Thanks

Appreciate your help,
ns

reading a string from a file with CFile Read()

nss9-Feb-03 6:40

nss

9-Feb-03 6:40

I have a file with several lines of text (all end with a carriage return). I want to use my CFile object to read these strings into an array of pointers to char. I dont see a anything like GetLine()....if I dont know the length of the text on the line, I dont have a value to give Read() as a count of chracters...
Actually I'm push_backing the strings onto a vector...

Re: reading a string from a file with CFile Read()

C^hris L^osinger9-Feb-03 7:12

C^hris L^osinger

9-Feb-03 7:12

try CStdioFile

-c

WWT2D?

Fractals

Thank you!!!!!

nss9-Feb-03 8:19

nss

9-Feb-03 8:19

That is working out......many thanks.

Calling functions in DLL

hongheo769-Feb-03 5:24

hongheo76

9-Feb-03 5:24

Hi,

I got a DLL (not MFC) with some functions in it. The header file containing the declaration for the functions of the DLL is also available.

Is there a way to call these functions in a static way other than using LoadLibrary and GetProcAddress ?

Thanks

Re: Calling functions in DLL

Roman Nurik9-Feb-03 5:29

Roman Nurik

9-Feb-03 5:29

yes, include the header file:

#include "MyDllBase.h"

and link the project with the output .LIB file for the DLL

under project settings->linker->input, add "MyDllBase.lib"

- Roman -

SIMPLE db example

JockeP9-Feb-03 4:58

JockeP

9-Feb-03 4:58

Hi!

I have tried to find a simple way to manipulate a database (in MS Access or MS SQL Server). However, I've not succeeded. I've tried SELECT statements with CRecordset and it works. But it seems like only SELECT statements work. This is what I've tried:

CDaoDatabase* m_pDB;
CDaoRecordset* m_pRS;
m_pDB = new CDaoDatabase;
m_pRS = new CDaoRecordset(m_pDB);

try {
m_pDB->Open("c:\\accessdb\\db1.mdb");
// CString strQuery = _T("SELECT * FROM Table1"); //Works just fine...
CString strQuery = _T("INSERT INTO Table1 VALUES ('3', 'Olga')"); //Doesn't work
m_pRS->Open(dbOpenDynaset, strQuery);
} catch (CDaoException* e) {
AfxMessageBox(e->m_pErrorInfo->m_strDescription);
e->Delete();
}

So how do you add data to a table, modify tables and so on?

Cheers,
Joachim

Re: SIMPLE db example

l a u r e n9-Feb-03 7:15

l a u r e n

9-Feb-03 7:15

im assuming the 3 in ur insert statement goes into a numeric field in the database table ... if so lose the '' around it ... u only have to quote text fields (and prolly date fields sometimes)

"even if my world is weird its my world"
biz stuff about me

Re: SIMPLE db example

Anonymous9-Feb-03 7:17

Anonymous

9-Feb-03 7:17

No, it's a text field

Re: SIMPLE db example

l a u r e n9-Feb-03 7:21

l a u r e n

9-Feb-03 7:21

ok well i use odbc for db stuff but it would seem to me that opening a dynaset on an insert statement wouldnt make sense ... u need to simple execute the statement against the db so prolly look for an .execute type command

"even if my world is weird its my world"
biz stuff about me

Re: SIMPLE db example

JockeP9-Feb-03 10:59

JockeP

9-Feb-03 10:59

ok thanks, but it need more specific ideas... i'm not that experienced with using vc++ to work with databases

Re: SIMPLE db example

Michael P Butler9-Feb-03 11:21

Michael P Butler

9-Feb-03 11:21

Do you really need to use DAO. ADO is a lot easier. Check out this link for some good examples.

http://www.codeproject.com/database/#ADO[^]

Michael

Wonder Woman, Wonder Woman.
All the world's waiting for you,
and the power you possess.

In your satin tights,
Fighting for your rights
And the old Red, White and Blue.

Re: SIMPLE db example

bryce9-Feb-03 15:30

bryce

9-Feb-03 15:30

JockeP wrote:
("INSERT INTO Table1 VALUES ('3', 'Olga')");

INSERT INTO Table1 (Field1, Field2) VALUES VALUES ('3', 'Olga')");

where field1 and field2 are obviously part of your table
(you didnt tell us the structure of your table)
Bryce

Re: SIMPLE db example

Solomon Wu9-Feb-03 18:22

Solomon Wu

9-Feb-03 18:22

Pls Using:
CDaoDatabase::Execute

Learning and Working

C++ template class and CDialog

Moak9-Feb-03 4:13

Moak

9-Feb-03 4:13

Hi,
it simply doesn't work... I'm right?

Imagine somthing like this.........

template <class T> class CDialogView : public CDialog 
{
 /*stuff*/ 
}

It will all compile fine until compiler hits the MFC message macros. At BEGIN_MESSAGE_MAP macro the template specification for the class causes the compiler to fail. A CDialog without message handlers makes no sense, that's why you can't simple skip the message macros. *sigh*

I had a look on Google's Usenet archive and found no solution.

Re: C++ template class and CDialog

Joaquín M López Muñoz9-Feb-03 4:57

Joaquín M López Muñoz

9-Feb-03 4:57

Check Yury Golstman's article Colored/Blinking Controls and Dialogs with any Font[^]. He features a most interesting technique to implement message maps for template class (view TemplDef.h in the source code).

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: C++ template class and CDialog

Moak9-Feb-03 12:08

Moak

9-Feb-03 12:08

Joaquín M López Muñoz wrote:
interesting technique to implement message maps for template class (view TemplDef.h in the source code)

looks very promising, thanks for the good help Joaquín!

OpenGL or DirectX ?

Ehsan Baghaki9-Feb-03 3:51

Ehsan Baghaki

9-Feb-03 3:51

Hi guys?
is it true that OpenGL is better than DirectX ?

-=Ehsan-de-Burge=-

Re: OpenGL or DirectX ?

Moak9-Feb-03 4:05

Moak

9-Feb-03 4:05

-=Ehsan-de-Burge=- wrote:
is it true that OpenGL is better than DirectX ?

no

Moak (who is actually using OpenGL because he likes it more)

Re: OpenGL or DirectX ?

Mike Nordell9-Feb-03 15:03

Mike Nordell

9-Feb-03 15:03

-=Ehsan-de-Burge=- wrote:
is it true that OpenGL is better than DirectX ?

That is an all too common question, that almost as often isn't qualified with "for this particular area" with an explanation of the area, making a "correct" answer impossible.

As a general 3D visualization API, OpenGL is most certainly better than DirectX. Actually, it's the only 3D visualization API widely recognized, and if you in any way or form would like to run your application on anything but Windows (including Wine) OpenGL is again the only recognised API.

If you on the other hand are prepared to limit your application to Windows only, and it seems you are prepared to do just that, DX is currently with the ATI 9700 a little ahead of OpenGL in terms of features - you can use more whistle and bells on todays highest-end PC consumer 3D card, the 9700 (Pro). But if you were interested in those "features" you'd already be knowing them, not having to ask this question. Smile | :)

For a more thorough examination, may I suggest you search the "advanced" forum over at opengl.org? There was a thread (a rather long thread, some months ago IIRC) a developer basically started with "This is it. I'm going DX". At the end of the thread he wrote something to the effect "OK, I'm convinced. Maybe DX wasn't such a great idea after all. OpenGL it still is for me".

But it still boils down to: What are you going to use it for, and are you prepared to pay the price if you go with DirectX?

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.