C / C++ / MFC Discussion Boards

Re: overloading operator[] question

Michael Dunn12-May-04 3:37

Michael Dunn

12-May-04 3:37

It's customary to write two [] overloads, one const and one not:

class X
{
public:
  X& operator[](int n);
  const X& operator [](int n) const;
};

The non-const version will be called for l-values, or r-values that contain a non-const X. The const version will be called for r-values that contain a const X.

Unfortunately you can't really tell from the non-const version whether it's returning an lvalue or rvalue.

--Mike--
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Calling a Class Member from a Tread

sweep12312-May-04 1:20

sweep123

12-May-04 1:20

I have a MFC Dialog based application which will update a Edit Box when an event is set. A thread is waiting on this event.

But how do I call a procedure from this thread to update this Edit Box.

2 questions;

1. How should this procedure be written (member of dialog or not)

2. I can pass in some data via a structure when I create the thread, but how can I pass in either a pointer to the Dialog or this procedure.

I did try passing in the dialog 'this' pointer but could not see the procedure;

CMyDialog::UpdateData() This is the update data procedure.

I am stuck - help

Re: Calling a Class Member from a Tread

jmkhael12-May-04 1:37

jmkhael

12-May-04 1:37

1. i would go for a member function
2. pass this then in the thread callback cast the pointer again to your dialog

(CMyDialog*) pxDlg = (CMyDialog*) pParam;

But personnaly, i would just pass the handle of the window, and post a message from the thread to this window
Check
SendMessage, PostMessage and RegisterWindowMessage

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: Calling a Class Member from a Tread

anderslundsgard12-May-04 1:39

anderslundsgard

12-May-04 1:39

Short answer for now:

Se

http://www.codeproject.com/threads/memberthread.asp

realy easy and Good!

...and justice for all

APe

Re: Calling a Class Member from a Tread

David Crow12-May-04 2:20

David Crow

12-May-04 2:20

sweep123 wrote:
CMyDialog::UpdateData() This is the update data procedure.

Be very careful when using UpdateData(). It can prove to be not very helpful.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Serialoze Problem

asv12-May-04 0:20

asv

12-May-04 0:20

hi,

We have created an activex Ctrl using MFC.

It has serialize method in its COleControl derived class.

Now myActiveX control is inserted in a powerpoint presentation.

Whenever power point slideshow ends, then the serialize method is getting called.

How to avoid serialize method is getting called at the end of slide show mode?

I am trying by setting SetModifiedFlag(false) but no result.

pls help me.

dadsadasd

Save Function

jazzlycool11-May-04 22:48

jazzlycool

11-May-04 22:48

I need help in doing a save function.

The program needs to save the text in the text field from a dialog into a text file. The dialog is called from the application which is in MDI form.

Thanks.

jazzlycool

Re: Save Function

toxcct11-May-04 23:31

toxcct

11-May-04 23:31

<font style="color:blue;">#include</font> <fstream>
<font style="color:green;">//...</font>
ofstream dest("\\fold\\my_file.txt");
Cstring Buffer;
(GetDlgItem(MY_CONTROL))->GetWindowText(Buffer);
dest << Buffer;
dest.close();

TOXCCT >>> GEII power

Re: Save Function

jazzlycool12-May-04 4:46

jazzlycool

12-May-04 4:46

Thank you very much. It works very well. Smile | :)

jazzlycool

Re: Save Function

toxcct12-May-04 4:48

toxcct

12-May-04 4:48

perfect, i wasn't 100% sure of me Big Grin | :-D

now i am... eheheh

TOXCCT >>> GEII power

Writing Class definitions

bhangie11-May-04 22:32

bhangie

11-May-04 22:32

Hi there

Can someone help me with this?
I need to write a program which simulates a computer system in a public library.

Working on these four objects - Customer, Books and loans
and the library itself.

The library needs to collect info about Customer and add customers.

Books title, isdn number and so forth.

Loans = the date loaned and date returned.

Customers must be able to loan books from and return books
to the library.

Library needs to print out a report containg details of each book and customer for each loan.

I would apreciate if some can just give me a starting point example of how to implement this.
Also links to places where i can go thru similar code

thanks in advance

Bhangie

Re: Writing Class definitions

Steve S11-May-04 22:37

Steve S

11-May-04 22:37

It's been a while since I did homework.
Here are some hints for my version.

Each object should encapsulate the data about the instance of the object. For a book, this would be title, author, isbn etc. You'd probably want a unique book id too, since a library may have multiple copies of popular books. For a loan, you want to record the book, the customer, and the start/return dates. If you want history you have to save these after books are returned.

A library is really a collection of other objects. You need some way for objects to persist. A librarian wouldn't type in the names of all the borrowers every day at system startup, or all the books.

Steve S

resize the workspace

Thevoidin11-May-04 21:44

Thevoidin

11-May-04 21:44

i want to develop the interface like ms-paint where theres a toolbox in which button like icons are drawn.also how to add scrolling capability to the interface as it is in paint.

Re: resize the workspace

Iain Clarke, Warrior Programmer11-May-04 21:57

Iain Clarke, Warrior Programmer

11-May-04 21:57

Try looking at CToolBar / CDialogBar for the toolbox bit,
and CScrollView for the scrolling interface.

For scrollview at least, there are some good scribble samples.

Iain.

about drag and drop

chpsoft11-May-04 21:24

chpsoft

11-May-04 21:24

hello!!

i try to drag items between listctrls in my application,but when i drag more than 8 items at one time,the dragmove operation is so slow.

i find that CImageList::DragMove function is so slow,but why?
and how to solve it?

help me!!

resize DC

wow999911-May-04 21:09

wow9999

11-May-04 21:09

Hi there

Is it passible to resize DC?

Thanks

Re: resize DC

Steve S11-May-04 22:32

Steve S

11-May-04 22:32

A DC doesn't have a size per se. What it has (generally) is a drawing surface (bitmap) associated with it. If it's a memory DC, you can select a different one in, but you'd have to be sure that the old one was managed properly.

Why do you want/need to do this?

Steve S

How to use put_Picture!?!

GFABBRI11-May-04 21:07

GFABBRI

11-May-04 21:07

1) Wath is the corret way to use "put_Picture" for an Image control if I have the Path of the Picture to load (C++ MFC)?

2)How can I find the Ptah of the application that is running?

Thank's for all
Cry | :((

Sorry for my English!!

Re: How to use put_Picture!?!

David Crow12-May-04 2:10

David Crow

12-May-04 2:10

GFABBRI wrote:
2)How can I find the Ptah of the application that is running?

Use GetModuleFileName(NULL, ...).

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: How to use put_Picture!?!

Jens Doose12-May-04 3:00

Jens Doose

12-May-04 3:00

I am not quite sure what kind of parameters put_Picture expects, but maybe you could try to get a IPicture object with "OleLoadPicture"?

Jens

Re: How to use put_Picture!?!

anlichang19-Apr-10 19:31

anlichang

19-Apr-10 19:31

I am meeting with this question,waiting for solution....

Clock on toolbar

Filomela11-May-04 21:06

Filomela

11-May-04 21:06

How can I put a clock on a button on the toolbar?
Thanks.

Re: Clock on toolbar

Iain Clarke, Warrior Programmer11-May-04 22:15

Iain Clarke, Warrior Programmer

11-May-04 22:15

You have a couple of choices that I can see:

1/ Have a really *huge* imagelist, and change the buttons image every minute to reflect the new time,

or

2/ Its for adding a combo box rather than a clock control, but the logic is the same: Toolbars with embedded Combo Boxes[^].
You just need a clock control now!
For example... CClockST v1.3[^]!

Good luck,

Iain.

Re: Clock on toolbar

Iain Clarke, Warrior Programmer11-May-04 22:42

Iain Clarke, Warrior Programmer

11-May-04 22:42

While looking for my own purposes, I also found:
How to place controls on toolbars[^].

Its amazing what you find when you look!

Iain.

Re: Clock on toolbar

Filomela12-May-04 20:14

Filomela

12-May-04 20:14

Thanks a lot.I have looked at the wrong place:codeguru.

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