Using a managed Dll from an unmanaged Win32 .EXE

[CharlesHenri]

Hello,

i plan to use a managed dll containing WinForm classes in an unmanaged
win32 exe.

Starting from NOTHING, how do i have to proceed ?

I have found the following tutorial on microsoft.com :

"Converting Managed Extensions for C++ Projects from Pure Intermediate
Language to Mixed Mode" :

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcmex/html/vcconconvertingmanagedextensionsforcprojectsfrompureintermediatelanguagetomixedmode.asp

I've tried to create an Win32 application + a managed c++ dll, and use
the dll in the exe, following step by step the tutorial.

All compiles and links, but....the application starts with an
uncontinuable exception 0x000005 (acces violation i presume).

What i am missing ? Anyone has a sample solution ?

I am using VS 2003 v 7.1.3088 with XP 2002 Professional.

Many Thanks !!

[William DePalo [MVP VC++]]

"CharlesHenri" <gdno75-...@yahoo.fr> wrote in message
news:1119883415.2...@g49g2000cwa.googlegroups.com...

> i plan to use a managed dll containing WinForm classes in an unmanaged
> win32 exe.
>
> Starting from NOTHING, how do i have to proceed ?

I should tell you that while I am familiar with interop I don't _do_
Winforms. I seem to recall a presentation in which it was mentioned that
VS.Net 2005 was going to include features that would make allow for some
easier MFC and Winforms interoperability. That's an option if you are
willing to use the beta in advance of the release.

Nevertheless, I can tell you that it is possible now to make a .Net class
appear to native code as a COM object. If you do that it is fairly easy to
call methods in managed classes from native code.

So, the first step is to give your class a dual interface:

using System;
using System.Runtime.InteropServices­;

namespace ClassLibrary1
{
[ClassInterface(ClassInterface­Type.AutoDual)]
public class Class1
{

public Class1()
{
}

public void SayHello()
{
Console.WriteLine("C# says hello!");
}

}
}

Then you can register the assembly and create a type library from it with
the
command

regasm /tlb:ClassLibrary1Lib.tlb ClassLibrary1.dll

That done, you can take advantage of the native compiler's ability to import
a type library and to create a C++ wrapper class from it:

#include <windows.h>
#import "mscorlib.tlb"

using namespace mscorlib;
#import "ClassLibrary1Lib.tlb"
using namespace ClassLibrary1;

int main()
{
CoInitialize(0);

_Class1Ptr class1(__uuidof(Class1));

class1->SayHello();

CoUninitialize();
return 0;
}

Finally, you put the assembly in the same directory as the executable et
voila.

Regards,
Will

[CharlesHenri]

Thanks very much Will,

i was aware of this solution, but i think it is quite impossible to use
it in the context of the application i manage to migrate.

from what i found on other forums i undestood that there are 3 main
solutions :

1- make the native exe and the dll communicating via COM (your
solution)
2- re-compile the whole solution (.exe + .dll) in the "It just works"
fashion
(see http://www.codeproject.com/managedcpp/nishijw01.asp as example)
3- use mixed mode

i want to be able to use .NET and Winforms from a HUGE existing
application (let's say 1500 classes, millions of code lines) that use
MFC, corba calls...etc

1. is excluded, 2. seems very difficult, few chance to compile and
link...that's why i was thinking of using the third solution.

Anyone have already done such a migration ?

sorry for poor english ;-)

William DePalo [MVP VC++] a écrit :

[Ronald Laeremans [MSFT]]

Hi,

You will need to debug the startup of the application to see exactly
what is going wrong. Post concrete findings here (like at least the call
stack and any investigation you mage to do) when you crash.

Ronald Laeremans
Visual C++ team