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problem with calling C++/CLI wrapper to C++ code from C# applicati

I need to write a C# application that uses unmanaged C++ code. I created a
C++/CLI wrapper to C++ code and encountered the following problem. Any time I
try to instantiate a wrapper in C# application the program crashes with an
"An unhandled exception of type 'System.IO.File NotFoundExcepti on' occurred
in mscorlib.dll, Additional information: The specified module could not be
found. (Exception from HRESULT: 0x8007007E)". C# application has a reference
only to the wrapper and the wrapper has a reference to unmanaged dll. Similar
application written in C++/CLI gives exactly the same error if it has a
reference only to the wrapper namespace. In case of C++/CLI application,
VS2005 allows to add a reference to unmanaged dll and then the application
works OK.
I have seen an example of managed C++ wrapper that is virtual identical to
the code below and is claimed to work with C#
Cannot figure out what is the problem with my code.
Here is the code

#define _CPPLIB_EXPORT_ IMPORT __declspec(dlle xport)
#define _CPPLIB_EXPORT_ IMPORT __declspec(dlli mport)

double _a;
double _b;
double _c;

CCppLib(double a, double b, double c);

bool IsValid();


CCppLib::CCppLi b(double a, double b, double c)
_a = a;
_b = b;
_c = c;

bool CCppLib::IsVali d()
return (_a + _b _c && _a + _c _b && _b + _c _a );


#pragma once
#include "..\\CppLib\\Cp pLib.h"

using namespace System;

namespace CLRWrapper

public ref class Triangle
CCppLib* _CppLib;


_CppLib = new CCppLib();

Triangle(double a, double b, double c)
_CppLib = new CCppLib(a, b, c);


if (_CppLib != NULL)
delete _CppLib;
_CppLib = 0;

CCppLib* GetCppLib() { return _CppLib;}

bool IsValid()
if (_CppLib != NULL)
return _CppLib->IsValid();
return false;


// CLRTest.cpp C++/CLI test application
using namespace System;
using namespace CLRWrapper;

int main(array<Syst em::String ^^args)
Triangle^ tr = gcnew Triangle(1, 2, 3);
Console::WriteL ine(tr->IsValid());

return 0;

//Program.cs C# test application

using System;
using System.Collecti ons.Generic;
using System.Text;
using CLRWrapper;

namespace TestTriangle
class Program
static void Main(string[] args)
Triangle tr = new Triangle(0.1, 0.2, 0.3);
Console.WriteLi ne(tr.IsValid() );

Dec 29 '06 #1
2 7251
"An unhandled exception of type 'System.IO.File NotFoundExcepti on' occurred
in mscorlib.dll, Additional information: The specified module could not be
found. (Exception from HRESULT: 0x8007007E)".
This error could have something to do with the manifest in debugging mode.
Try to generate and embed the manifest in the assembly (linker/manifest

I found this out by using the procmon utility to see what file the loader
was looking for (msvcr80d.dll).
Dec 29 '06 #2
It occured to be my error unrelated to anything written in the post.
If directories are properly assigned everything works fine.
Jan 5 '07 #3

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