C / C++ / MFC

Re: Logging to a text file

13-Sep-01 5:21

If you're concerned with "lot of load", use CreateFile with FILE_FLAG_WRITE_THROUGH flag, and keep the file open.

KB article Q99794 has more info.

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

User 988513-Sep-01 5:22

User 9885

13-Sep-01 5:22

Thank you very much for the prompt reply. I will check that out.
Thanks again.

- Thomas

modified 29-Aug-18 21:01pm.

Copying files

13-Sep-01 5:06

I have to admit, I'm somewhat new to C++, so this question may not seem like much to a lot of the readers.

Using one of the common header files, is there a simple way to copy a file from place to place, modifying its name if necessary? I'm aware of how to do this using text files with fstream, but I'm curious about how to copy other file types.

If anyone responding would rather give a code example that try to explain it otherwise, I'll give you a scenario... say you're aiming to write a quick program that would copy the file c:\windows\desktop\file1.bmp to c:\copyoffile1.bmp.

Any help would be appreciated. Thanks.

Re: Copying files

Tomasz Sowinski13-Sep-01 5:09

13-Sep-01 5:09

Use one of the following Windows API functions:

CopyFile
SHFileOperation

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

Re: Copying files

13-Sep-01 5:16

Got it to work. Thanks for the help.

Dependencies

13-Sep-01 5:02

In windows NT, when you would right click on a dll, you could view its dependncies and what not.

How do you do that in 2000?

Re: Dependencies

Tomasz Sowinski13-Sep-01 5:17

13-Sep-01 5:17

It's not related to the operating system. There's a program, depends.exe, installed with VC++ that associates itself with .dll files. Copy this file to W2K machine or install VC++ and you'll get 'View dependencies' option.

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

C++

13-Sep-01 4:26

I had a question for recommendations...let's say you learned some C++, and then after that, got into MFC and Windows Programming.

After 2 years of that, you feel that you don't know C++ too well, but you are not too bad either..you are kind of intermediate.

what book would you recommend to use for someone at this stage, trying to take his C++ to the next level, going from intermediate to senior?

Michael P Butler13-Sep-01 4:39

Michael P Butler

13-Sep-01 4:39

It depends on what you mean by going to the next level. What do you want to learn?

In my experience, books can only take you so far with C++. After that you learn a lot more by coding and making mistakes (and correcting them).

What do you feel you lack?

Michael Smile | :)

Tomasz Sowinski13-Sep-01 4:40

13-Sep-01 4:40

Which books have you read so far?

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

[James Pullicino]13-Sep-01 4:46

[James Pullicino]

13-Sep-01 4:46

I strongly recommend these two books:

Effective C++
Scott Meyers
ISBN: 0-201-92488-9

More Effective C++
Scott Meyers
ISBN: 0-201-63371-X

(2b || !2b)

learn STL / templates

C^hris L^osinger13-Sep-01 4:46

C^hris L^osinger

13-Sep-01 4:46

there's a lot of good stuff in STL (how to use it, the philosophy behind it, etc.) and templates in general are a good intermediate step.

and really, once you've mastered templates and STL, there's not much left, just more of the same.

-c

------------------------------
Smaller Animals Software, Inc.
http://www.smalleranimals.com

Re: learn STL / templates

13-Sep-01 5:00

thanks all...I'll follow up on these..

as for the gent, who asked me what I have read thus far..I started off with Deittel & Deittel, then got into Windows and MFC, with Charles Petzold and Jeff Prosise books. So, I haven't really dealth with STL and some other areas of C++ that Windows programming really doesn't get involved in, too much.

thanks

Tomasz Sowinski13-Sep-01 4:50

13-Sep-01 4:50

and really, once you've mastered templates and STL, there's not much left

There's much left. "Modern C++ Design" by Alexandrescu has a lot of advanced-level metaprogramming/generic programming stuff.

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

Tomasz Sowinski13-Sep-01 5:15

13-Sep-01 5:15

For improving your C++, I'd recommend Bjarne Stroustrup's "C++ Programming Language". The author is the C++ creator, so you'll get first-hand information. After this, read two Scott Meyers' books listed in previous posts. You may also have a look at http://www.gotw.ca/ - this is C++ Guru of The Week website.

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

_CrtIsValidHeapPtr

Derek Lakin13-Sep-01 2:04

13-Sep-01 2:04

Is there a release build equivalent of the _CrtIsValidHeapPtr function?

Derek Lakin.
Salamander Software Ltd.

Tomasz Sowinski13-Sep-01 2:08

13-Sep-01 2:08

No. Why do you need this functionality in release?

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

Derek Lakin13-Sep-01 2:17

13-Sep-01 2:17

I'm building a TabCtrl extension class that allows the tab pages to be created from a dialog resource.

Inside the tab control it normally creates a new instance (using new) and keeps that pointer in a list. However, if you want to do anything complicated on the tab then you need to inherit from the default tab page class (CTabPage) to provide the handling of events, etc. Therefore there is an AddPage override which accepts a pointer to a CTabPage and just adds it to the internal list.

The destruction code for the tab control just iterates through the list calling delete. However, if the pointer passed in wasn't created with new then it will crash. I wanted to avoid having to create objects with new outside of the tab control class and allow them to be deleted by the tab control class.

So, if in the destruction routine I could determine if the pointer was a valid heap pointer then I could delete it, otherwise I would just leave it and let it's destructor do the work.

Am I making sense?

Derek Lakin.
Salamander Software Ltd.

Tomasz Sowinski13-Sep-01 2:28

13-Sep-01 2:28

Item 27 in Meyers' "More Effective C++" deals with related issues. He presents some methods of determining if object is on the heap or not, however, there's no simple solution to this problem.

Here's what I would do in this case:

Assume that clients are responsible for deleting pages if it's necessary (many of them will simply create their pages as data members in dialog class or as local stack-allocated objects). Clearly document client code responsibility and everything should be OK.

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

Derek Lakin13-Sep-01 2:34

13-Sep-01 2:34

many of them will simply create their pages as data members in dialog class or as local stack-allocated objects

That's most of the problem. The default approach is for the tab control to do all of the new'ing and deleting of the objects required for the tab pages. If a client creates a local stack-allocated object and passes a pointer to it for the tab control, then the tab control tries to call delete on it.

Derek Lakin.
Salamander Software Ltd.

Tomasz Sowinski13-Sep-01 2:45

13-Sep-01 2:45

So there are two overloads of AddPage, right?

void AddPage(UINT nResID);
void AddPage(CTabPage *page);

You need to keep not only the page pointer, but a boolean value meaning 'tab control created this page'. To avoid code duplication, create new private method that adds the page to internal list. Note the second parameter.

private:
void RealAddPage(CTabPage *page, bool bOwnedByMe);

AddPage methods should call ReadAddPage passing true or false respectively:

void CYourTab::AddPage(CTabPage *page)
{
RealAddPage(page, false);
}
void CYourTab::AddPage(UINT nResID)
{
CTabPage *page = new CTabPage(nResID);
// do whatever you need to fully construct page
RealAddPage(page, true);
}

In destructor, you'll iterate through list of pages and call delete only on those created with a call to AddPage accepting resource ID.

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

Derek Lakin13-Sep-01 3:02

13-Sep-01 3:02

This is pretty much the approach I was moving too.

Thanks for your help.

Derek Lakin.
Salamander Software Ltd.

Dialog Resizing

13-Sep-01 1:34

Hi Everybody...
I am having a problem in resizing the CFileDialog. I have derived a class from CFileDialog and then i placed a button on that dialog now what i want to do is that i want to resize that dialog with this button. I have made it but unfortunately when i ran this application on Win2000. what is happening the list control that shows the contents of the current folderis resizing instead dialog....

I am using this code:

CFileDialog* pFileDlg = (CFileDialog*)CWnd::FromHandle(hwnd)
COptionsFileDialog *pFileDialogEx = (COptionsFileDialog *)pFileDlg ;
pFileDialogEx->SetWindowPos(0, 0, 0, 590, size , SWP_NOZORDER);

Is any one has an idea what is happening yar....

Rose

Re: Dialog Resizing

Tomasz Sowinski13-Sep-01 2:04