Consuming C# dll from unmanaged C++ exe; StringCollectio n

[eSapient]

I have a case where a C# dll is being consumed by an unmanaged C++
executable. One of the dll methods returns a StringCollectio n object. What
are the requirements for the C++ executable in terms of .h, .tlb files to be
included/imported, and the syntax for consuming the StringCollectio n object?

TIA.

[Ben Voigt]

"eSapient" <eS******@discu ssions.microsof t.comwrote in message
news:7F******** *************** ***********@mic rosoft.com...

>I have a case where a C# dll is being consumed by an unmanaged C++
executable. One of the dll methods returns a StringCollectio n object. What
are the requirements for the C++ executable in terms of .h, .tlb files to
be
included/imported, and the syntax for consuming the StringCollectio n
object?

You can use .NET via COM, see "Runtime Callable Wrapper". However that
might not be the easiest way to go.

Is the .dll a hard dependency (exe can't work without it) or a soft
dependency (lose some features but press forward)?

If it is a hard dependency, then your exe is actually dependent on the .NET
framework (exe needs dll needs framework). In that case, see if your exe
works correctly when built with /clr.

>
TIA.

[eSapient]

I created a .NET class library with the following C# code:

using System;
using System.Runtime. InteropServices ;
using System.Collecti ons.Specialized ;

namespace ClassLibrary3
{
[GuidAttribute(" 6F66DEAB-1BCF-4ce4-AB06-D298BA2B56CA")]
public class MyClass : IMyClass
{
public MyClass()
{}

void IMyClass.MyMeth od(out StringCollectio n strings)
{
strings = new StringCollectio n();
strings.Add("Fi rst string");
strings.Add("Se cond string");
}
}

[GuidAttribute(" F26D63B9-C3A8-4f1a-9B17-1C441DE58EAF")]
public interface IMyClass
{
void MyMethod(out StringCollectio n strings);
}
}

I registered this project for COM Interop.

I then created a console application in VC++, where I added a reference to
the class library project (both projects are in the same solution). I am not
very familiar with COM programming using C++. My intention is to consume the
class library above in unmanaged C++. I added the following code in the
console application, but it is incomplete since I don't know how to go about
it.

#include "stdafx.h"

#import "mscorlib.t lb"
//#import "..\ClassLibrar y3\bin\Debug\Cl assLibrary3.tlb "

#using <mscorlib.dll >

using namespace System;
using namespace System::Collect ions::Specializ ed;
//using namespace ClassLibrary3;

int _tmain()
{
::CoInitialize( 0);
ClassLibrary3:: IMyClassPtr pIMyClass(__uui dof(ClassLibrar y3::MyClass));
// pIMyClass.MyMet hod();

return 0;
}

Can somebody help me and show me how to consume the .NET class?

Thanks in advance.