C / C++ / MFC

Luc Pattyn5-Jan-09 16:06

Luc Pattyn

5-Jan-09 16:06

Hi,

is (char*)malloc(301); what you are looking for?

if so, don't forget to call free() eventually.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Love, happiness and fewer bugs for 2009!

PhuLove7-Jan-09 1:58

PhuLove

7-Jan-09 1:58

Hi Luc Pattyn, thank you for your help.

But I still haven't know yet.
Do you mean:

//lpBuff = rcvBuff.GetBuffer(300);<br />
rcvBuff = (char*)malloc(301);

Then... the relation of 'lpBuff' with 'rcvBuff'?

Please help me!

thank you for helping

Luc Pattyn7-Jan-09 2:12

Luc Pattyn

7-Jan-09 2:12

Hi,

in C a string is just a pointer pointing to a number of bytes containing (or intended to contain)
a sequence of characters ending on a NULL; so either you already have a string, and hence you have
the pointer, or you need to create one, and then you call malloc.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Love, happiness and fewer bugs for 2009!

PhuLove7-Jan-09 13:54

PhuLove

7-Jan-09 13:54

hi Luc Pattyn,

Thank you for yor help.
I have a question.

//lpBuff = rcvBuff.GetBuffer(300);<br />
rcvBuff = (char*)malloc(301);

Then

//rcvBuff.ReleaseBuffer(100);<br />
free(rcvBuff);

is this right? I think that 100 and 300 are related.

please help me!

thank you for helping

Luc Pattyn7-Jan-09 14:19

Luc Pattyn

7-Jan-09 14:19

Hi,

I don't know what your 100 would stand for.

to undo a malloc you call free() without arguments; you can only free the entire buffer, which should be OK.

There are more specialized functions but I have never needed them at all.

You know there is such a thing as documentation that tells you all the details you may ever need...

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Love, happiness and fewer bugs for 2009!

PhuLove8-Jan-09 14:52

PhuLove

8-Jan-09 14:52

Hi Luc Pattyn,

Anyway, thank your for your help Smile | :)

thank you for helping

MFC and dynamic_cast?

nobaq5-Jan-09 10:32

nobaq

5-Jan-09 10:32

Hello,

Is there any reason why dynamic_cast<> is turned off in my MFC projects by default?

I always get (in Debug and Release builds).

warning C4541: 'dynamic_cast' für polymorphen Typ 'CWnd' mit /GR- verwendet; unvorhersehbares Verhalten möglich

Is there any reason to not add the /GR switch?

Why is this not done by default?

The whole C-style casting with objects in the MFC code itself is really bad coding style anyway (C-style casts should not be used any more in C++)

Regards,
Niki

CPallini5-Jan-09 10:40

5-Jan-09 10:40

What about documentation [^]?
It looks like you're using Visual Studio 2003 or earlier.
Smile | :)

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

[My articles]

Mark Salsbery5-Jan-09 10:45

5-Jan-09 10:45

Heh. I was wondering how old the Visual Studio version had to be.

I can't remember the last time RTTI wasn't enabled by default.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

CPallini5-Jan-09 23:05

5-Jan-09 23:05

According to documentation [^] Visual Studio 2003 is old enough.
Smile | :)

Mark Salsbery6-Jan-09 5:01

6-Jan-09 5:01

According to my age, my memory doesn't go back that far Poke tongue | ;-P

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

CPallini6-Jan-09 5:12

6-Jan-09 5:12

According to the photograph in your CodeProject member's page, you're not that old. Roll eyes | :rolleyes:

Mark Salsbery6-Jan-09 5:14

Re: MFC and dynamic_cast? [modified]

6-Jan-09 5:14

That was taken when I was 40.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Jijo.Raj5-Jan-09 10:53

Jijo.Raj

5-Jan-09 10:53

For determining class relations at runtime, MFC have its own mechanism called RTCI(Runtime Class Information) which is similar to RTTI in C++. You can resolve class relations by using CRuntimeClass::IsKindOf() etc.

[Edit] With respect to Pillani's reply.
~~So its obvious that C++ RTTI will be switch offed by default, since MFC itself is providing support. Enabling two similar stuffs at same time helps only to reduce performance.~~

I'm not sure, but i think that the RTCI evolved and exists together with RTTI due to historic reasons.

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

modified on Monday, January 5, 2009 5:12 PM

How to use C# class library dll controls in C++ Win32 project

nobaq5-Jan-09 12:24

nobaq

5-Jan-09 12:24

Thank you very much, I've enabled it now and use dynamic_cast.

Yes, I habe VS 2003 .NET.

Niki

atisman5-Jan-09 10:02

atisman

5-Jan-09 10:02

Hi,
I'm a long-time C++ programmer and relatively new in C#.
I have not been working with UI-related stuffs for a while.
Recently I had a project that is related to a GUI-based application, which requires a custom-style listview control. I found some listview controls in "the code project" that may fit to my purpose. But most of them are written in C# and it's output is a Class Library (DLL). In general, is there any way for me to use those custom listview controls written in C# in my Win32 C++ project (using Visual Studio 2005)? Or is it simply impossible? Thanks a lot for your help in advance.

Re: How to use C# class library dll controls in C++ Win32 project

Hamid_RT5-Jan-09 21:21

Hamid_RT

5-Jan-09 21:21

I think you can use of it on the c++ and vice versa.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Limit on MFC apps running at one time?

Zigoto005-Jan-09 9:22

Zigoto00

5-Jan-09 9:22

I needed to run multiple instances of an MFC Application. During testing I realized that there is a limit to the number of instances I can run (sometimes 86 other 101). After reaching this limit I couldn't even run a different MFC app unless I terminated some of the running instances. Does anybody know what is the cause of this behavior? Thanks.

Re: Limit on MFC apps running at one time?

CPallini5-Jan-09 10:09

How can I remove a Window border (title bar etc) using HWND via Win32 after the window has been created?

5-Jan-09 10:09

Surely there's a limit on system resources, When the 180th instance of my MFC test application crashes, it was probably failing CreateWindow.
Smile | :)

Steve_5-Jan-09 7:22

Steve_

5-Jan-09 7:22

The graphics library I am using provides basic window functionality, painting, moving etc, but for anything more complex it provides the HWND to each window so we can call Win32 stuff.

My Win32 knowledge is limited, how can I alter the window style using the HWND? I've done some searching but haven't found anything - probably because I'm looking for the wrong thing.

Any help would be great! Smile | :)

Steve

Re: How can I remove a Window border (title bar etc) using HWND via Win32 after the window has been created?

CPallini5-Jan-09 7:39

Re: How can I remove a Window border (title bar etc) using HWND via Win32 after the window has been created?

5-Jan-09 7:39

You may change the window style at runtime using SetWindowLong function [^].
Smile | :)

Steve_5-Jan-09 8:15

Steve_

5-Jan-09 8:15

Thanks,

I have made the following call:

SetWindowLong(window.getHWND(), GWL_EXSTYLE, WS_EX_CLIENTEDGE);

I also call SetWindowPos as stated in the documentation to cause the changes to appear. The window visibly changes. How would I specify that I want to remove or hide the window border and title bar? I have looked at the documentation for Window Styles and CreateWindowEx but am unsure how to achieve this.

I'm looking to achieve something similar to the result of the following .NET code:

myForm.BorderStyle = FormBorderStyle.None;

Thanks again!

Steve

Re: How can I remove a Window border (title bar etc) using HWND via Win32 after the window has been created?

Code-o-mat5-Jan-09 9:12

Code-o-mat

5-Jan-09 9:12

Try something similar to:

SetWindowLong(window.getHWND(), GWL_STYLE, GetWindowLong(window.getHWND(), GWL_STYLE) & ~WS_BORDER);

IF this doesn't work, try instead of WS_BORDER the other, border related styles like WS_DLGFRAME (see here[^] for window styles.)

> The problem with computers is that they do what you tell them to do and not what you want them to do. <

Re: How can I remove a Window border (title bar etc) using HWND via Win32 after the window has been created?

Mark Salsbery5-Jan-09 9:15