使用C＃项目的一种解决方案中的本机C ++ dll

Question

I have a source file written in C++, performing some simulation. I would like to create a user interface for this in C#. How can I have both C++ and C# in a single Visual Studio solution?

What I did so far was I created a .NET C# project and solution, and then a native project as a DLL library. I have marked the C# project as "Depends on" the C++ dll. I have provided the necessary dllexport directives and imported using DllImport . Everything compiles fine, but when I execute the application, the dll is not found:

Unable to load DLL 'xxxx.dll': The specified module could not be found.

It is no surprise the DLL is not found, as the application is run from its output directory and the output directories are different for the C# and C++ projects. I do not want to write an explicit path as my import like `"..\\..\\Debug\\xxxxx.dll".

Is there some common way how to structure a solution containing native a Dll and C# app so that the C# app can call the native Dll?

Answer 1

If you know that after deployment your C++ DLL will be in the same folder as your C# DLL (or executable), then on simple way to solve the problem is to use the PostBuild event (Project properties, Build events).

You can add a copy command that will put your C++ DLL into the C# output folder.

Answer 2

I found a very comfortable way, which might have some unexpected drawbacks, but I do not see any so far: I can enable CLR for the C++ DLL project, making it "mixed", even if it in fact does not contain any managed code, and then the project building it can be made a Reference in the C# .NET project.

To make the project mixed mode set Configuration Properties / General / Common Language Runtime Support to Common Language Runtime Support (/clr) .

After this the build system copies the DLL into the application output folder automatically.