A continued saga of C# interoprability with unmanaged C++
- by Gilad
After a day of banging my head against the wall both literally and metaphorically, I plead for help:
I have an unmanaged C++ project, which is compiled as a DLL. Let's call it CPP Project. It currently works in an unmanaged environment. In addition, I have created a WPF project, that shall be called WPF Project. This project is a simple and currently almost empty project. It contains a single window and I want it to use code from Project 1. For that, I have created a CLR C++ project, which shall be called Interop Project and is also compiled as a DLL.
For simplicity I will attach some basic testing code I have boiled down to the basics.
CPP Project has the following two testing files:
tester.h
#pragma once
extern "C" class __declspec(dllexport) NativeTester
{
public:
void NativeTest();
};
tester.cpp
#include "tester.h"
void NativeTester::NativeTest()
{
int i = 0;
}
Interop Project has the following file:
InteropLib.h
#pragma once
#include <tester.h>
using namespace System;
namespace InteropLib {
public ref class InteropProject
{
public:
static void Test()
{
NativeTester nativeTester;
nativeTester.NativeTest();
}
};
}
Lastly, WPF Project has a single window refrencing Interop Project:
MainWindow.xaml.cs
using System;
using System.Windows;
using InteropLib;
namespace AppGUI
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
InteropProject.Test();
}
}
}
And the XAML itself has an empty window (default created).
Once I am trying to run the WPF project, I get the following error:
System.Windows.Markup.XamlParseException: 'The invocation of the constructor on type 'AppGUI.MainWindow' that matches the specified binding constraints threw an exception.' Line number '3' and line position '9'. --- System.IO.FileNotFoundException: Could not load file or assembly 'InteropLib.dll' or one of its dependencies. The specified module could not be found.
at AppGUI.MainWindow..ctor()
Interestingly enough, if I do not export the class from CPP Project, I do not get this error. Say, if i change tester.h to:
#pragma once
class NativeTester
{
public:
void NativeTest()
{
int i = 0;
}
};
However, in this case I cannot use my more complex classes. If I move my implementation to a cpp file like before, I get unresolved linkage errors due to my not exporting my code. The C++ code I want to actually use is large and has many classes and is object oriented, so I can't just move all my implementation to the h files.
Please help me understand this horrific error I've been trying resolve without success.
Thanks.
