C / C++ / MFC Discussion Boards

Maxwell Chen17-Mar-08 23:00

17-Mar-08 23:00

George_George wrote:
why do you want to call Bar and Pimpl in method Test of class Y? If we put something (like Bar) in Pimpl part, it means it is not visible. So, I think it does not make senses to access Bar if it is in Pimpl part. Any comments?

My code sample was just sort of excerpt. After all, you have to deal with class X or class Y in real life.

Let's take CDialog::OnInitDialog() of MFC for example. You created a dialog based project, so you have the below code.

In function implementation of CTestDlg::OnInitDialog, you need to do many things. For example: calling the base's member function CWnd::GetSystemMenu() to manipulate the title-box menu; calling CWnd::SetIcon to manipulate icons, etc.

class CTestDlg : public CDialog  // class Y : public X
{
protected:
  virtual BOOL OnInitDialog(void);
  // ...
};
BOOL CTestDlg::OnInitDialog()
{
  // ...
  CMenu* pMenu = GetSystemMenu(FALSE); // This is something like invoking X::Bar().
  // ...
}

The article and I are not talking it making sense or not to access Bar if it is moved into Pimpl; We are talking about: Sometimes a certain design paradigm will shoot your own feet.

George_George wrote:
I think you can still access Foo in class Y, right?

See my answer to (1) as the above.

My questions to you:
1) George, are you still at school or are you working at some company?
2) After you have been asking various beginner ~ expert level questions, do you really feel you are getting better in C++?
3) Are the questions you have asked here really useful to your homework or your real-world job?

Maxwell Chen

Re: Inheritance in Pimpl idiom

George_George17-Mar-08 23:26

George_George

17-Mar-08 23:26

Thanks Maxwell,

I have read and understand the sample. Do you mean the pattern of MFC dialog is good or not? Does it relates to my original question?

My answers to your 3 questions,

1) private Smile | :)

2) sure, expecially from you;
3) some from books, some from the comments from you.

regards,
George

Re: Inheritance in Pimpl idiom

Maxwell Chen17-Mar-08 23:53

Maxwell Chen

17-Mar-08 23:53

George_George wrote:
Do you mean the pattern of MFC dialog is good or not?

I am not a MFC pro. Nor am I so much picky.
Things working smoothly will do. As cats being able to catch mice are considered good cats. Big Grin | :-D

And I sometimes branch the patterns to what I want. (I am evil.) Laugh | :laugh:

George_George wrote:
Does it relates to my original question?

Yes it does dedicate to asnwering your original question, regarding class X and the derived Y.

Maxwell Chen

Re: Inheritance in Pimpl idiom

George_George18-Mar-08 0:17

George_George

18-Mar-08 0:17

Thanks Maxwell,

I read the MFC dialog sample and compare with my original question again.

1. The MFC sample as you mentioned, is good sample, flexible without any restriction to mesh-up base class parts and derived class parts into a function. And it provides flexible inheritance architecture in this way.

2. What I am asking in the original question, is about the limitation of the handle/body pattern when doing inheritance.

So, your sample (1) provides flexible way and the question I am asking is about limitations and uselessness (2), do they related? I am confused.

It is appreciated if you could provide more description. Smile | :)

regards,
George

Copy File and long file path

vikramlinux17-Mar-08 19:26

vikramlinux

17-Mar-08 19:26

Hi All,
I am trying to use CopyFile API for long file names (file name > 256)

When I specify
src: Normal path
dest: Long path

It works !

But when I specify
src: Long path
dest: Normal path

It fails saying "File Name or ext is too long"

Anybody knows the reason?

Re: Copy File and long file path

Michael Dunn17-Mar-08 19:45

Michael Dunn

17-Mar-08 19:45

From the documentation[^]:

In the ANSI version of this function, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "\\?\" to the path. For more information, see Naming a File[^].

--Mike--
Visual C++ MVP Cool | :cool:

LINKS~! CP SearchBar v3.0 | C++ Forum FAQ

I work for Keyser Söze

Re: Copy File and long file path

vikramlinux17-Mar-08 20:23

vikramlinux

17-Mar-08 20:23

Thanks a lot for your quick soln.

shutdown function for CWinApp()

rp_suman17-Mar-08 18:49

rp_suman

17-Mar-08 18:49

I want to open the MIDI port at startup of the application and close it when the application is shutting down.
I am thinking of opening the port in InitInstance() function.
Which function should I use to close the port?

Thanks,
Suman

Re: shutdown function for CWinApp()

rp_suman17-Mar-08 18:53

rp_suman

17-Mar-08 18:53

It is ExitInstance() function.

Thanks,
Suman

Re: shutdown function for CWinApp()

Rajkumar R17-Mar-08 21:37

Rajkumar R

17-Mar-08 21:37

Its seems you know the answer when posted the question (only 4 min difference)

Re: shutdown function for CWinApp()

rp_suman18-Mar-08 4:30

rp_suman

18-Mar-08 4:30

Rajkumar R wrote:
Its seems you know the answer when posted the question (only 4 min difference)

Hi, not like that, after I have posted question, I was searching index help in vc++ IDE, got the function in "members" link. I might have saw it before posting it. I thought of deleting the question, but it may be useful for some other user, or atleast I will not ask it again.
Thanks for your comment.

Best Regards,
Suman Big Grin | :-D

Change writing direction in RUN TIME (Edit Box)

Joseph Marzbani17-Mar-08 9:50

Joseph Marzbani

17-Mar-08 9:50

I'm sorry to post this question twice! But I realy need it...
My question is how can I change writing direction in an edit box in
RUN-TIME? (Right/Left Alignment)

Re: Change writing direction in RUN TIME (Edit Box)

CPallini17-Mar-08 9:53

CPallini

17-Mar-08 9:53

See here.

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Re: Change writing direction in RUN TIME (Edit Box)

David Crow17-Mar-08 10:57

David Crow

17-Mar-08 10:57

Usef Marzbani wrote:
I'm sorry to post this question twice! But I realy need it...

But you already got it. Roll eyes | :rolleyes:

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Change writing direction in RUN TIME (Edit Box)

led mike17-Mar-08 11:39

led mike

17-Mar-08 11:39

DavidCrow wrote:
But you already got it.

Maybe he can't understand your reply because you wrote it Left to Right. Poke tongue | ;-P

led mike

background worker

Adnan Merter17-Mar-08 8:00

Adnan Merter

17-Mar-08 8:00

i need to create a function that can stop a process which takes long time.

i mean the user can stop the process while it is processing(just like a cancel buton). can i do this by using "backgroung worker"? i found some example code and information in C# but i couldnt in C++.

do i have to use multithreading?

Re: background worker

C^hris L^osinger17-Mar-08 8:11

C^hris L^osinger

17-Mar-08 8:11

strictly speaking you don't have to. but the alternatives can be pretty ugly, and even more trouble than using a worker thread.

use a worker thread.

image processing toolkits | batch image processing

Re: background worker

led mike17-Mar-08 9:25

led mike

17-Mar-08 9:25

Well unless your code is doing the processing you can't stop it without terminating the worker thread waiting on the process, which is not recommended.

led mike

delete line in the file

specialhaha17-Mar-08 7:23

specialhaha

17-Mar-08 7:23

Hi all,
How can I delete some lines in the file using CFile?
Many thanks for your help

Re: delete line in the file

C^hris L^osinger17-Mar-08 7:26

C^hris L^osinger

17-Mar-08 7:26

1. create a temp file
2. while (! end-of-file)
3. read line
4. if line is not the one you want to delete
5. write line to your temp file
6. loop to 2

7. copy temp file over your source file

image processing toolkits | batch image processing

Re: delete line in the file

specialhaha17-Mar-08 7:40

specialhaha

17-Mar-08 7:40

Thanks
I wonder if there is a method or function directly doing it.
Many thnaks for your answer

Re: delete line in the file

Cedric Moonen17-Mar-08 8:22

Cedric Moonen

17-Mar-08 8:22