Unmanaged C++ in C#

Questions
- Using Unmanaged C++ Dynamic Library (DLL) in .NET Applications
- Using DllImport for read a unmanaged dll
- How to Create DLL in Visual Studio 2008 in Visual C++ for Using in C#
- Call an Unmanaged DLL from .Net Windows Application
- Call an Unmanaged Visual C++ code from Managed Code like C# or other .NET

Solution
I have received a request from my friend, He wanted to have a solution with an unmanaged library (DLL) as core and a windows form application in C# as an interface. You can find a very simple solution with 2 languages, here.

- Microsoft Visual C++ 2010 (Unmanaged, Dll)
- Microsoft Visual C# 2010 (Managed, Windows Form)

ClassLibrary.h

// ClassLibrary.h
#define DllExport _declspec(dllexport)
extern "C" DllExport int Sum(int, int);
extern "C" DllExport wchar_t getChar(void);
extern "C" DllExport wchar_t* getString(void);

#pragma once
int Sum(int, int);
wchar_t getChar(void);
wchar_t* getString(void);

ClassLibrary.cpp

#include "stdafx.h"
#include "ClassLibrary.h"

int Sum(int a, int b){return a + b;}
wchar_t getChar(){return L'ن';}
wchar_t* getString(){return L"امیرمهدی خادم آستانه";}

part of Form1.cs

[DllImport("c:\\ClassLibrary.dll", CharSet = CharSet.Unicode)]
[return : MarshalAs(UnmanagedType.I4)]
public static extern Int32 Sum(Int32 a, Int32 b);

[DllImport("c:\\ClassLibrary.dll", CharSet = CharSet.Unicode)]
public static extern char getChar();

[DllImport("c:\\ClassLibrary.dll", CharSet = CharSet.Unicode)]
public static extern String getString();

Download
[1] Unmanaged C++ in C# Solution (both of VC and C# projects) download