Assigning a member variable... - C / C++ / MFC Discussion Boards

Davide Pizzolato2-Jul-02 7:07

2-Jul-02 7:07

hDIB is a HBITMAP, not a HANDLE.
go here:
http://www.codeproject.com/bitmap/cximage.asp
and see the difference between CreateFromHBITMAP() and CreateFromHANDLE().

Re: bitmap writing problem

Speedy3-Jul-02 11:04

Speedy

3-Jul-02 11:04

abey kitni dafa question poochay gaa, bataya tha na key tiberian sun ki cd day kar jaa phir sab sawaloon ka jawab mil jaye gaa. Mad | :mad:

Preallocate a map

2-Jul-02 6:49

Here's a couple of typedefs I'm using

typedef map<cstring, cstring=""> A;
typedef map<cstring, a=""> B;
typedef map<cstring, b=""> C;

I can have anywhere from 4 to 8 C's
Each C can have ~30 B's
And Each B can have anywhere from 2 to 250 A's

The reason a map was choosen is because the speed of searches is the most important and these will only be built once (no adds or deletes).

To build these maps takes about 5 seconds (1.7 Ghz PIV). That's not so bad except a GUI can't be displayed until the maps are built. It looks a little sloppy having that lag.

Anyway, I trying to find a way to speed up the building of these maps. I'm guess that if I can preallocate the maps to a typical usage (4 C's 30 B's and 150 C's), that would improve things.

Any ideas?

Re: Preallocate a map

Joaquín M López Muñoz2-Jul-02 11:01

Joaquín M López Muñoz

2-Jul-02 11:01

Are you building your maps top-down (first As, then Bs, finally Cs) or bottom-up? The latter order is likely to be way faster, since Bs and Cs store copies of the enclosed types. So, instead of writing

A a;
B b;
//insert stuff into a
b["Hello"]=a;

you should write

B b;
A& a=b["Hello"]; //note the & to access directly b["Hello"] instead of create a copy
//insert stuff into a

Other ways to improve your code:

Define B as a map<CString,A*> (and similarly wih C) to prevent excessive copying. If this imposes a problem with keeping track of the objects (to do the final cleanup), consider some ref-counted smart pointer instead.

Give my block allocator a try (though I wouldn't expect but a modest improvement thru its use.)Good luck.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Re: Preallocate a map

markkuk2-Jul-02 21:23

markkuk

2-Jul-02 21:23

In your case (no inserts or deletes), you could achieve similar search performance and faster building with sorted vectors and binary_search algorithm.

Re: Preallocate a map

Alexandru Savescu2-Jul-02 22:49

Alexandru Savescu

2-Jul-02 22:49

If you use .NET then you may consider using hash_map

Best regards,
Alexandru Savescu

view2 will not show when selected from file/new

ns2-Jul-02 6:02

2-Jul-02 6:02

Hello,

I tested the folowing things:

1. With a CView based MDI project, I added a second document with a CFormView. Butr when I run it and choose the new document I get a debug/assert in viewform.cpp.

Next I tried so that both docs have views based on CFormView. Same problem. View1 shows fine, view2 asserts. ANy ideas?
Thanks,
ns

Assigning a member variable...

RuiSantiago2-Jul-02 5:53

RuiSantiago

2-Jul-02 5:53

Hi! I've just created a button by code, and i would like to have in the same class where it has been created, its control member variable, what i have is :

botao->Create("Cancel", WS_CHILD|WS_VISIBLE, CRect(10, y+120, 60, y+170), this, 1232123);

I use this ast argumento to give it a name and then i edited Resource.h and write : #define IDNB_TESTE 1232123, 'assigning' that id number to a name, which i would use in DDX:
DDX_Control(pDX, IDNB_TESTE, m_teste);

then i tried to use the m_teste variable, but i kept receiving errors, what ave i done wrong? How can i do this?

Thank you for your time

Re: Assigning a member variable...

RuiSantiago2-Jul-02 6:14

RuiSantiago

2-Jul-02 6:14

I found it, i had just to had BS_PUSHBUTTON and process the ON_BT_CLICKED message with the id i had chose to the function.

Thank you the same

Class Wizard Visual C++ 6.0 (DAO) can not recognize MS Access 2000 format

2-Jul-02 5:28

Hi,

I use Visual C++ 6.0 and have problem working with MS Access Database 2000:

a) After I created a database table with MS Access 1997, then later if I use Class Wizard (in Visual C++ 6.0) to add a new class with DAO option (CdaoRecordSet or CDaoRecordView) ... there is no problem, every thing working fine!

b) But if I created a database table with MS Access 2000, then when I add a new class with DAO option (CdaoRecordSet or CDaoRecordView) ... it did not allow and said "unrecognized format"

- I did add this code: AfxGetModuleState()->m_dwVersion = 0x0601; to let Visual C++ recognize new driver, I also download "DaoPatch.dll" and put it into \Program Files\MS Visual Studio\VC98\Setup\1033 & \Program Files\MS Visual Studio\Common\Wizzard98 ... still had the same problem!

- Even I tried to update with Microsoft Visual Studio 6.0 Service Pack 5 that claimed improvement some problem with DAO 3.6 files (Dao header & cpp files... the result is the same!

*) I know it should work, but I do not know how to do it? Can any one help me?

I am really appreciate it! Thanks.

Thanh Chau

Re: Class Wizard Visual C++ 6.0 (DAO) can not recognize MS Access 2000 format

#realJSOP2-Jul-02 6:27

#realJSOP

2-Jul-02 6:27

You need the latest version of MDAC. You can probably get it off the MS web site.

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receiving messages in mdi

ns2-Jul-02 5:27

2-Jul-02 5:27

I found this function:

LRESULT CMainFrame::OnTestMessageLParam(WPARAM wParam, LPARAM lParam)

used by some sample code. But when I went to "add windows messsage handler" in the mainframe class context menu I didnt see any thing like wm_message or something. SO where is this function coming from and what does it respond to? Shouldnt it have been in the context menu?

Re: receiving messages in mdi

Mike Nordell2-Jul-02 8:01

Mike Nordell

2-Jul-02 8:01

If you are using MFC you most surely have the source code also. Search the MFC src directory for OnTestMessageLParam.

Newbie to Direct3D question

Joel Holdsworth2-Jul-02 5:24

Joel Holdsworth

2-Jul-02 5:24

Hi There,
Does anybody know the best way of rendering a 2d circle outline onto 3d device of a known number of pixels readius? I've tried rendering it by making vertex buffer with some points arranged in a circle drawn in close proximity to the camera, but it seems to be a bit of a convoluted way of going about it... Does anybody know a better way of overlaying 2d shapes into the buffer?

Thanks for you help...

With time we live, with money we spend!
Joel Holdsworth

Re: Newbie to Direct3D question

Mike Nordell2-Jul-02 8:05

Mike Nordell

2-Jul-02 8:05

Draw a plain circle on a bitmap and the use it as a texture.

Since this is also how it's done in OpenGL you might have a look at e.g. "NeHe Productions" or opengl.org (note, you might get biased against proprietary API's using free information like this :->).

another mdi question

ns2-Jul-02 5:09

2-Jul-02 5:09

My app will have only two MDI docs and two views (one for each). No new views or windows can be created. I want to show (or spawn) doc2 and view2 in response to a buttonclick on view1. Then after the user has finished entering data in view2, I want to click a button, get rid of view2 (destroy or hide), and show view1 (updated) again. How do I go about doing this?

I am working on how to get view1 the info returned by view2 in a separate thread.Thanks so much,
ns

having trouble creating two docs for a CFormView MDI

ns2-Jul-02 4:39

2-Jul-02 4:39

I added classes for the second doc and view and added the template. Wouldnt compile. I compared it with a successful example with uses CViews , not CFormViews. My CFOrmView view code differed from the CView code,: the constructor wasnt argumentless and was public, and there was no dyncraete staement. SO I moved the declaration of my cosntructor to protected and added the dyncreate statement, but still wont compile. What am I doing wrong or not doing?
Thank you!

Re: having trouble creating two docs for a CFormView MDI

C^hris L^osinger2-Jul-02 4:41

C^hris L^osinger

2-Jul-02 4:41

ns wrote:
but still wont compile

what are the error messages???

-c

Garbage collection, making life better - for weenies!

Image Processing - easy, like Sunday morning.

Re: having trouble creating two docs for a CFormView MDI

ns2-Jul-02 4:53

2-Jul-02 4:53

Thanks so much for the interest. I used class wizard to make my view and doc files (the second doc)

The example with CView that works has:

from .h
protected:
CMDIBillView(); // protected constructor used by dynamic creation
DECLARE_DYNCREATE(CMDIBillView)

and from .cpp

IMPLEMENT_DYNCREATE(CMDIBillView, CView)

CMDIBillView::CMDIBillView()
{
}

I just noticed that:
The implement line was missing in my view code (CFOrmView based)
so I added
IMPLEMENT_DYNCREATE(CMDIKVView, CFormView)

plus the other changes noted below. Now only 1 error:

C:\Trainer\mditalk\MDIKVView.cpp(16) : error C2512: 'CMDIKVView' : no appropriate default constructor available

My second view class has the following relevant code (I moved the constructor to protected and added dyncreate - it didnt show up by default as is does in a CView based example I made)

From the .h file:

protected:
CMDIKVView(CWnd* pParent /*=NULL*/); // protected constructor used by dynamic creation
DECLARE_DYNCREATE(CMDIKVView)

From the cpp file:
CMDIKVView::CMDIKVView(CWnd* pParent /*=NULL*/)
: CDialog(CMDIKVView::IDD, pParent)
{
//{{AFX_DATA_INIT(CMDIKVView)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
}

The example with CView that works has:

from .h
protected:
CMDIBillView(); // protected constructor used by dynamic creation
DECLARE_DYNCREATE(CMDIBillView)

and from .cpp

IMPLEMENT_DYNCREATE(CMDIBillView, CView)

CMDIBillView::CMDIBillView()
{
}

I just noticed that:
The implement line was missing in my view code (CFOrmView based)
so I added
IMPLEMENT_DYNCREATE(CMDIKVView, CFormView)

plus the other changes noted below. Now only 1 error:

C:\Trainer\mditalk\MDIKVView.cpp(16) : error C2512: 'CMDIKVView' : no appropriate default constructor available

Re: having trouble creating two docs for a CFormView MDI

ns2-Jul-02 5:45

2-Jul-02 5:45

Well,

It turns out that my second document I accidentally derived from CDIalog, whereas I wanted CFormView. So things are okay regarding my troubles with that. Which brings me to the question: Does one not make a view derived from CDialog in MDI?

Re: having trouble creating two docs for a CFormView MDI

C^hris L^osinger2-Jul-02 6:27

C^hris L^osinger

2-Jul-02 6:27

ns wrote:
Does one not make a view derived from CDialog in MDI?

no. one does not Smile | :)

use CFormView instead.

-c

Garbage collection, making life better - for weenies!

Image Processing - easy, like Sunday morning.

passing variables between Doc and View in MDI

2-Jul-02 4:24

Hello,

This is in regards to MDI architecture.

I have a CString that gets set to (lpszPathName) on the OpenDocument function inside the Doc class.

I want to access this string in the View class, and I don't know how to access it.

I tried this.
(in Doc Class)
m_String = lpszPathName;
AfxMessageBox(m_String);

This MessageBox display the Pathname as I wanted.

(in View class)
CMyView NewView;
AfxMessageBox( NewView.m_String );

This MessageBox displays a blank box. Obviously, the string isn't passing as I thought it would.

Does anyone know how I could do this?

Thanks a whole lot.

Re: passing variables between Doc and View in MDI

#realJSOP2-Jul-02 4:31

#realJSOP

2-Jul-02 4:31

You have to get a pointer to the view's associated document first.

CMyDoc* pDoc = (CMyDoc*)GetDocument();
if (pDoc)
{
   AfxMessageBox((LPCTSTR)pDoc->m_String);
}

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"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

Please review the Legal Disclaimer in my bio.

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