Managed C++/CLI

Re: Can't deliver MediaSample to two different output pins - Directshow problem

7-Oct-08 4:36

You may get an answer, but generally DirectShow questions
don't get much love here.

I know there's a couple MVPs that really know this stuff....you can
find them here:

MSDN DirectX.Video Newsgroup[^]

Hope that helps!
Mark

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

Mark Salsbery9-Oct-08 8:25

Re: Can't deliver MediaSample to two different output pins - Directshow problem

9-Oct-08 8:25

Hi itchy,

I see you're getting a little help over on the other board.

I was just thinking, if you're delivering the same samples to both
output pins, why not just use a single output pin into an infinite tee filter?

Just a random thought,
Mark

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

itchy239-Oct-08 21:09

itchy23

9-Oct-08 21:09

Yeah I'm getting help, but up until now nothing is working.
I know I could use the inftee filter, but I don't want that because I'm making changes to both samples. If I use inftee filter I need to write 2 filters.
Besides its good practice, if it would work Wink | ;)

.

Thanks by the way for redirecting me.

Event handling in C

massaslayer6-Oct-08 4:39

massaslayer

6-Oct-08 4:39

I've read this thing: http://www.codeproject.com/KB/winsdk/console_event_handling.aspx[^]

but it's still not clear where i put the codes...

the main idea is:

that the user is not possible to close the console window by pressing X.

Please help me, i've spend houres searching

Re: Event handling in C

Mark Salsbery6-Oct-08 6:26

Program too big to fit in memory

6-Oct-08 6:26

Please post on the Visual C++/MFC board[^].

This board is for Managed C++/CLI questions only.

Mark

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

Cyrilix3-Oct-08 10:57

3-Oct-08 10:57

I have a Managed C++ Windows Forms program that I'm compiling in Visual Studio 2003. When I try to run it, it tells me "Program too big to fit in memory" in a command prompt.

Does anyone know why it would even pop up with a command prompt window when this is a Windows application? Secondly, why would I get this error? Sources from google tell me that usually, this has to do with a corrupt installer issue, but this is not an installer at all.

Thanks.

Cyrilix3-Oct-08 13:00

3-Oct-08 13:00

I think I might've found the issue. I believe it lies with trying to reference an unmanaged lib (not compiled with managed extensions in C++), from a project that is compiled into a managed executable (managed extensions enabled). From what I've read, it seems to me (so far) that the only way to do this is to use a .dll and PInvoke, but is there any way to simply use a .lib?

Mark Salsbery3-Oct-08 14:49

3-Oct-08 14:49

The lib should work fine. C++/CLI lets you call code in static and
dynamic libraries without p/invoke.

Mark

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

Cyrilix3-Oct-08 21:44

3-Oct-08 21:44

Hi Mark,

Thanks for the info, however, here's the problem. The first time I do a build, it always fails with a LNK1000 error where essentially, VC7's link.exe throws some kind of exception. If I try to build it again, it succeeds. Always. The only problem is, that the generated executable is invalid. At first, I couldn't figure out what was wrong. Then, because I suspected some kind of dependency issue, I ran depends.exe on the generated executable, and it told me that the PE header was invalid (or something to that effect). Then, that was where I suspected the managed/unmanaged stuff.

I should also note that I have a solution of 3 projects, 1 of which is the executable (managed), 1 of which is a static library (managed), 1 of which is a static library (unmanaged). If I remove the unmanaged static library from its reference list or dependency chain, building the executable complains about linker errors (as expected, since I have not defined the symbols). As soon as I add the unmanaged static library, I get the LNK1000.

Mark Salsbery4-Oct-08 7:13

4-Oct-08 7:13

Cyrilix wrote:
1 of which is a static library (managed)

I'm not sure how well that's going to work, nor can I find any
solid confirmation one way or the other.

Binding of managed types in a library is done at the assembly level.
I'm not sure how well the linker's going to handle that.

A managed class library (DLL) is the appropriate way to make a managed
library (even if it has native code in it as well).

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

Cyrilix4-Oct-08 8:45

4-Oct-08 8:45

Well, the way it works is that I have a managed static lib that contains my __gc classes. Then, I have an unmanaged static lib depending on and using the managed static lib that contains regular (non __gc) classes, which is sort of my interface to the native world. I've been able to use this interface with other classes from native code without problem. Then, I have a Winforms app which depends on that native interface. Now that I think of this, it doesn't really make sense as to why I'm doing it this way. I'm sort of going Managed->Unmanaged->Managed... might as well see if I can cut out the middle layer.

Mark Salsbery4-Oct-08 7:24

4-Oct-08 7:24

Cyrilix wrote:
I'm compiling in Visual Studio 2003

I definitely recommend moving to at least VS 2005 (VC 8) any way you can,
as soon as you can, before investing a lot of time in code that is incompatible
with newer/future C++ compilers.

With VC8+, you get the actual C++/CLI language instead of the Managed Extensions
you are using with VC7, which aren't supported anymore (there's a compiler switch
to allow it...for now).

The Managed Extensions for C++ syntax is deprecated.

Mark

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

Cyrilix4-Oct-08 8:46

String conversion in c++/CLI

4-Oct-08 8:46

I am pushing for this as well, but I'm not sure if I'll be able to convince them to allocate hours to upgrade our entire system before I finish this small project. Also, I think the Managed C++ in VC8+ definitely also looks much nicer in terms of syntax.

Robin Imrie1-Oct-08 4:05

Robin Imrie

1-Oct-08 4:05

Hi,

I am porting my vc2003 app to vc2008 and have come across somthing like this...

// this defined
LPCTSTR lpsz = _T("myString");

// then later
// where Afunc is defined as
// SomeObject* AFunc( String *str );
SomeObject *obj = Afunc( lpsz );

under vc2003 this compiles and works file however in vc2008 it seems that i need to do...

// this defined
LPCTSTR lpsz = _T("myString");

// then later
// where Afunc is defined as
// SomeObject^ Afunc( String ^str );
SomeObject ^obj = Afunc( gcnew String(lpsz) );

the documentation on string literals in C++/CLI migration primer suggest that the following could be done.

SomeObject ^obj = AFunc( safe_cast<string^>(lpsz) );

this is wrong as it not compile.

I not sure the gcnew string( lpsz ) method is ideal. is there a better way or what is the propper way of doing this.

thanks

Robin

Re: String conversion in c++/CLI

led mike1-Oct-08 4:36

led mike

1-Oct-08 4:36

Robin Imrie wrote:
I not sure the gcnew string( lpsz ) method is ideal. is there a better way or what is the propper way of doing this.

in general gcnew is how you create managed objects in C++/CLI so that is always a correct way to do it. Of course strings can be different like in Native C++ based on what you need them for. In your code you are creating a native string and then converting it to a managed string.

If you only need a managed string then you could do this.

System::String^ lpsz = "myString";

There is a series of introductory C++/CLI articles here on CodeProject. I suggest you take advantage of them.

led mike

Re: String conversion in c++/CLI

Robin Imrie1-Oct-08 4:45

Robin Imrie

1-Oct-08 4:45

Thanks mike for that i had suspected as much.

Will give the C++/CLI articles a good look.

gtk installation

SeshaSridhar1-Oct-08 1:00

SeshaSridhar

1-Oct-08 1:00

Hi all,

We installed gtk from the following site
http://crossfire.real-time.com/clients/win32_gtk.html
please help us how to compile and run our own c++ files

Thank You
Sesha Sridhar

Error while calling VC# function in VC++

Andy Rama29-Sep-08 0:36

Andy Rama

29-Sep-08 0:36

Hi to all,

I have an 'Windows Form Control Library' "VideoWindow.dll" in VC#.Net 2008, having code as following,

<block><br />
    using DirectShowLib;//C# DirectShow Library<br />
<br />
<br />
    public partial class VideoWindow : UserControl<br />
    {<br />
        public VideoWindow()<br />
        {<br />
            InitializeComponent();<br />
        }<br />
<br />
        Label m_picVideoWindow = new Label();<br />
<br />
        public int SetPreview(IVideoWindow vwRenderer)<br />
        {<br />
            int hr = 0;<br />
            if (m_picVideoWindow.Bounds.IsEmpty)<br />
                return hr;<br />
            try<br />
            {<br />
                hr = vwRenderer.put_WindowStyle(WindowStyle.Child | WindowStyle.ClipChildren | WindowStyle.ClipSiblings);<br />
                DsError.ThrowExceptionForHR(hr);<br />
                hr = vwRenderer.put_Owner(m_picVideoWindow.Handle);<br />
                DsError.ThrowExceptionForHR(hr);<br />
                hr = vwRenderer.SetWindowPosition(0, 0, m_picVideoWindow.Width, m_picVideoWindow.Height);<br />
                DsError.ThrowExceptionForHR(hr);<br />
                hr = vwRenderer.put_Visible(OABool.True);<br />
                DsError.ThrowExceptionForHR(hr);<br />
            }<br />
            catch (Exception ex)<br />
            {<br />
            }<br />
            return hr;<br />
        }<br />
    }<br />
</block>

When I am calling SetPreview() from my VC++.Net 2008 MFC Application as follows,

<block><br />
IVideoWindow	*pWidnow;//C++ DirectShow Library<br />
CWinFormsControl<VideoWindow::VideoWindow> *a1 = new CWinFormsControl<VideoWindow::VideoWindow>();<br />
<br />
(*a1)->SetPreview(pWidnow);<br />
</block>

It gives compile error as,
error C2664: 'VideoWindow::VideoWindow::SetPreview' : cannot convert parameter 1 from 'IVideoWindow *' to 'DirectShowLib::IVideoWindow ^'

Please help me to solve this error.

Regards,
Aniket A. Salunkhe

led mike29-Sep-08 4:31

led mike

29-Sep-08 4:31

Aniket Salunkhe wrote:
Please help me to solve this error.

Well a Native C++ pointer

Aniket Salunkhe wrote:
IVideoWindow *pWidnow;

Is not going to be convertible to a managed object.

Aniket Salunkhe wrote:
DirectShowLib::IVideoWindow ^

If you don't know that, then you need to do some studying of C++/CLI basics and fundamentals. There is a series of CLI beginner articles here on Code Project.

led mike

Mark Salsbery29-Sep-08 7:27

29-Sep-08 7:27

Aniket Salunkhe wrote:
When I am calling SetPreview() from my VC++.Net 2008 MFC Application as follows,

IVideoWindow *pWidnow;//C++ DirectShow Library
CWinFormsControl<videowindow::videowindow xmlns:videowindow="#unknown"> *a1 = new CWinFormsControl<videowindow::videowindow>();

Handles to managed objects use ^, not * in C++.
Also you use gcnew, not new, to allocate them on the managed heap.

Aniket Salunkhe wrote:
(*a1)->SetPreview(pWidnow);

Huh?

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

George L. Jackson1-Oct-08 3:21

George L. Jackson

1-Oct-08 3:21

Mark, FYI, Aniket Salunkhe is trying to call managed code from native C++ according to this quote: "When I (Aniket Salunkhe) am calling SetPreview() from my VC++.Net 2008 MFC Application ...".

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Mark Salsbery1-Oct-08 4:51

1-Oct-08 4:51

That was pretty obvious from the error message as well Smile | :)

I only commented about the syntax/language use.
I suppose I could have mentioned that (s)he'll have to
compile with /CLR.

Cheers,
Mark

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

Andy Rama3-Oct-08 19:16

Andy Rama

3-Oct-08 19:16

Mark Salsbery wrote:
he'll have to
compile with /CLR.

I am already using this flag (/CLR).

Mark Salsbery4-Oct-08 6:42