从C＃.NET应用程序调用C / C ++代码

Question

I have a c++ application, i need to call it's class methods from C# app

I have followed the following tutorial and created a DLL file for the C++ app

http://msdn.microsoft.com/en-us/library/ms235636.aspx

When i tried to add a reference for the DLL file it gives me error message

a reference to could not be added please make sure that the file is accessible and that it is a valid assembky or COM component

Answer 1

You cannot add an unmanaged DLL as a reference. What's more, you cannot consume C++ classes from an unmanaged DLL in C#. Here are your options:

1. Compile the C++ code into a mixed mode C++/CLI assembly, and wrap the unmanaged C++ classes in ref classes. These can be consumed by C# in the usual way by adding the mixed mode C++/CLI assembly as a reference.
2. Wrap the unmanaged C++ classes with COM wrappers, and consume these from C# as you would any other COM library.
3. Wrap the C++ classes with C style functions and consume them from C# using p/invoke.

Of these options, the first is usually to be recommended.