C / C++ / MFC Discussion Boards

12-Sep-01 3:27

Hello,

Where can i find information in order to access data in an
*.mdb file using a console application under VC++6.0.
(I will need I/O access).

Thanks for help.

Re: How to access Access Base in VC++6.0

Martin Ziacek12-Sep-01 3:46

Martin Ziacek

12-Sep-01 3:46

Try this:

http://msdn.microsoft.com/library/en-us/daosdk/html/dadidx01_3inr.asp?frame=true

or

http://msdn.microsoft.com/library/en-us/daosdk/html/davcsdk_5jcf.asp?frame=true

Martin

Re: How to access Access Base in VC++6.0

Carlos Antollini12-Sep-01 3:49

Carlos Antollini

12-Sep-01 3:49

You have some options, that depends of wich technology you want to use.
For example you can use DAO, for that you have the CDAODatabase, CDAORecordset, etc, classes. You can use CDatabase Class usin ODBC, or you can use ADO, or OLE DB, for those you can find a lot of article in this site....

Good Luck!!! Smile | :)

Carlos Antollini.

unknow output debbug message

12-Sep-01 3:17

hello !
when i try to debug my application, the following message appear to the
output window :
`First-chance exception in Democreator.exe (GDI32.DLL): 0xC0000005: Access Violation`

What does it mean ?

Thanks.

F.Julien

Re: unknow output debbug message

Tomasz Sowinski12-Sep-01 3:26

Tomasz Sowinski

12-Sep-01 3:26

KB article Q105675 has some information.

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

Re: unknow output debbug message

Carlos Antollini12-Sep-01 3:43

Carlos Antollini

12-Sep-01 3:43

From MSDN:

<br />
First and Second Chance Exception Handling <br />
<br />
Microsoft Win32 Application Programming Interface (API) included with: <br />
<br />
<br />
    - Microsoft Windows NT versions 3.1, 3.5, and 3.51<br />
    - Microsoft Windows 95 version 4.0<br />
<br />
<br />
Structured exception handling (SEH) takes a little getting used to, particularly when debugging. It is common practice to use SEH as a signaling mechanism. Some application programming interfaces (APIs) register an exception handler in anticipation of a failure condition that is expected to occur in a lower layer. When the exception occurs, the handler may correct or ignore the condition rather than allowing a failure to propagate up through intervening layers. This is very handy in complex environments such as networks where partial failures are expected and it is not desirable to fail an entire operation simply because one of several optional parts failed. In this case, the exception can be handled so that the application is not aware that an exception has occurred. <br />
<br />
However, if the application is being debugged, it is important to realize that the debugger will see all exceptions before the program does. This is the distinction between the first and second chance exception. The debugger gets the "first chance," hence the name. If the debugger continues the exception unhandled, the program will see the exception as usual. If the program does not handle the exception, the debugger will see it again (the "second chance"). In this latter case, the program normally would have crashed had the debugger not been present. <br />
<br />
If you do not want to see the first chance exception in the debugger, then disable the feature. Otherwise, during execution, when the debugger gets the first chance, continue the exception unhandled and allow the program to handle the exception as usual. Check the documentation for the debugger that you are using for descriptions of the commands to be used. <br />

Cheers!!!

Carlos Antollini.

Re: unknow output debbug message

Rashid Thadha12-Sep-01 5:36

Rashid Thadha

12-Sep-01 5:36

Its a M$ known problem, It only Occurs in Win95 or Win98 - Best thing is to ignore it, as long as its not crashing your APP

Re: unknow output debbug message

12-Sep-01 6:15

Perhaps you should read the article above. It is not limited to Win9x.

Also, it is MS, or Microsoft not M$

CreateWindow

Nick Armstrong12-Sep-01 3:12

Nick Armstrong

12-Sep-01 3:12

I have a dialog which I have set as a tool window so it is always on top. Within this window I want to dynamically load buttons each with a different bitmap on. Someone has suggested that I use CreateWindow and pass a flag to say it will be of style BUTTON so I use the following code

CreateWindow("BUTTON",
"sample",
BS_BITMAP,
5,
5,
100,
100,
m_hWnd,
NULL,
NULL,
NULL);

I'm assuming that m_hWnd member variable should be a handle to the dialog box when it is shown, but when tested comes through as NULL and nothing is shown in the dialog box. What am I doing wrong?

Thanks for any help in advance

Nick

Re: CreateWindow

12-Sep-01 3:20

you must call ShowWindow() function after CreateWindow().

F.Julien

Re: CreateWindow

Nick Armstrong12-Sep-01 3:38

Nick Armstrong

12-Sep-01 3:38

thanks, but do I put those in the constructor of the containing dialog because obviously the buttons will be part of this. When doing this I get an assertion error, I think its talking about a NULL handle to this dialog which I thought would be a problem.

Nick

Re: CreateWindow

Steen Krogsgaard12-Sep-01 4:19

Steen Krogsgaard

12-Sep-01 4:19

Don't call CreateWindow on the buttons in the dialog's constructor - the dialog window won't be created yet so you can't use it as a parent window. Call CreateWindow in CYourDialog::OnCreate() (if you use MFC) or in response to the WM_CREATE msg (if non-MFC) instead. Since it's a dialog you can also put the calls in OnInitDialog/WM_INITDIALOG instead.

Cheers
Steen.

"To claim that computer games influence children is rediculous. If Pacman had influenced children born in the 80'ies we would see a lot of youngsters running around in dark rooms eating pills while listening to monotonous music"

Re: CreateWindow

Nick Armstrong12-Sep-01 5:01

Nick Armstrong

12-Sep-01 5:01

thanks a lot, that worked fine

Nick
Big Grin | :-D

Re: CreateWindow

Carlos Antollini12-Sep-01 3:34

Carlos Antollini

12-Sep-01 3:34

You need to call to ShowWindow Function, but you are missing same values in the style parameter like WS_CHILD | WS_VISIBLE whit this last parameter don't you need to call to ShowWindow function.

Cheers

Carlos Antollini.

Re: CreateWindow

Tomasz Sowinski12-Sep-01 3:36

Tomasz Sowinski

12-Sep-01 3:36

Button style should contain WS_CHILD and WS_VISIBLE:

CreateWindow("BUTTON", 
"sample", 
WS_CHILD | WS_VISIBLE | BS_BITMAP, 
5, 
5, 
100, 
100,
m_hWnd, 
NULL, 
NULL, 
NULL);

You should also pass a child window id after m_hWnd.

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

Re: CreateWindow

Nick Armstrong14-Sep-01 3:39

Nick Armstrong

14-Sep-01 3:39

How do I get this child window ID?

So far I have the following code:

CreateWindow( "BUTTON",
"sample",
WS_CHILD | WS_VISIBLE | BS_BITMAP,
5,
5,
20,
20,
m_hWnd,
/*the child window ID will go here*/,
NULL,
NULL);

HBITMAP hBmp = (HBITMAP)::LoadImage(AfxGetInstanceHandle(), "c:\\1.bmp", IMAGE_BITMAP, 16, 16, LR_LOADFROMFILE);

::SendMessage((HWND)hButton, BM_SETIMAGE, (WPARAM)IMAGE_BITMAP, (LPARAM)hBmp);

Thanks for the help so far

Nick

Re: CreateWindow

Tomasz Sowinski14-Sep-01 3:49

Tomasz Sowinski

14-Sep-01 3:49

How do I get this child window ID?

You don't get this ID, you have to come up with one yourself. This ID is passed back (as LOWORD(wParam) in WM_COMMAND) to the parent window when somebody clicks the button - you'll need to recognize which button was pressed, right?

You can use any scheme to create IDs to your buttons.

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

Re: CreateWindow

Nick Armstrong14-Sep-01 3:59

Nick Armstrong

14-Sep-01 3:59

So for example, I could set it as 966 by doing

int hButton = 966;

and including hButton under/after the m_hWnd parameter, because I already tried that. If that is correct, there is something else wrong, probably in the loading of the bitmap because when the program is run it show's no bitmap on the button.

Nick

Re: CreateWindow

Tomasz Sowinski14-Sep-01 4:18

Tomasz Sowinski

14-Sep-01 4:18

hButton is a window handle, not a child ID. Store value returned from CreateWindow in hButton. Use some predefined constant and pass it as child ID to CreateWindow. Use the same constant when handling WM_COMMAND - you'll be able to respond differently to different buttons being pressed.

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

Re: CreateWindow

Nick Armstrong14-Sep-01 4:30

Nick Armstrong

14-Sep-01 4:30

Sorted, thank you very much, much appreciated.

Nick

Big Grin | :-D

Re: CreateWindow

uzziah012-Feb-09 11:57

uzziah0

12-Feb-09 11:57

This is exactly what I'm doing, but in WM_COMMAND all WPARAM wp ever is is 0x0000FFFF

any ideas why?

I set it to
#define BTN_ONE 301

Thanks

allocate memory

Gérald Mercet11-Sep-01 23:41

Gérald Mercet

11-Sep-01 23:41

I would like to create a function which could return 2 COleDateTime objects simultaneously, so i think that i could use a pointer of COleDateTime. But, as i'm a beginner in C++, i would like to know if someone could show me how we could do the allocation of this pointer, his deletion, and how i could return the dates, as i want the function return dates?

thanks in advance

gerald

Re: allocate memory

Bernhard12-Sep-01 0:09

Bernhard

12-Sep-01 0:09

You create the Objects dynamically

COleDateTime* pDate1 = new COleDateTime();
COleDateTime* pDate2 = new COleDateTime();

These objects are not gonna be destroyed if you leave the scope of this function !!

You can acess all the member - Fun´s and Var´s by using the -> operator:

pDate1->GetStatus();

You wanna get rid of them:

delete pDate1;
delete pDate2;

if this helps you... fine.. if not.. you can ask me..

Bernhard

- I heard if you play the Windows CD backwards, you get a satanic message.
- That's nothing, if you play it forward, it installs Windows!

Re: allocate memory

Gérald Mercet12-Sep-01 0:16

Gérald Mercet

12-Sep-01 0:16

ok with your answer, but how could i return the values of 2 dates with 1 function?

Re: allocate memory

Joaquín M López Muñoz12-Sep-01 0:27

Joaquín M López Muñoz

12-Sep-01 0:27

May I suggest you use a struct holding the two dates just like this:

typedef struct{
  COleDateTime firstDateTime;
  COleDateTime secondDateTime;
}PairCOleDateTime;

and have your function return a PairCOleDateTime instead of a pointer. This way you get rid of all sorts of allocation/deallocation problems, and the extra cost of returning this struct by value should be negligible for most purposes.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

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