How do I add a reference to an unmanaged C++ project called by a C# project?

Question

One solution (the.sln)

One C++ project (mycppproject.vcxproj in 2010or mycppproject.vcproj in 2008) which compiles a native DLL exporting some function(s). In debug

Answer 1

Visual Studio doesn't support referencing an unmanaged C++ project from a managed C# one, but MSBuild supports referencing any project from any other project.

You can manually add a reference to your project by editing the .csproj file by hand. In the file, find your existing set of ProjectReference elements (or add a new ItemGroup if you don't have one) and add the following reference:

  {b402782f-de0a-41fa-b364-60612a786fb2}
  mycppproject
  false
  Content
  PreserveNewest

When you perform the build, the reference will cause MSBuild to build the referenced project first. The ReferenceOutputAssembly value tells MSBuild not to copy the output assembly of the build (since the C++ project does not produce one), but the OutputItemType and CopyToOutputDirectory values instruct it to copy the output content to the referencing project's output folder.

You will be able to see the reference in Visual Studio, but you can't do much with it there.

This answer is based on a similar problem solved by Kirill Osenkov on his MSDN blog: https://blogs.msdn.microsoft.com/kirillosenkov/2015/04/04/how-to-have-a-project-reference-without-referencing-the-actual-binary/