Question

I have a DLL in C++ with a funcion like the following:

LesMes.hpp

bool Sing_For_Me(CInstructment accompaniedBy, string song, string singer);

Meanwhile in my WPF app I was going to use the interop layer:

[ DllImport( "musicals.dll", EntryPoint="Sing_For_Me", CharSet=CharSet.Ansi )]
public static extern bool SingForMe(???????, string note, string singer);

How do I reference a CInstrument in the WPF code?

There seem to be lots of examples of strings being used, can you only use certain pre defined datatypes or something?

Answer 1

There isn’t any direct P/Invoke sort of way for C++ classes, but this is why C++\CLI was made.

You should make a C++\CLI Class project and there you can wrap CInstrument into a .NET class and then use that in WPF.

See this codeproject article for more info

Native C++ code just works with C++\CLI, there’s something called IJW (it just works). Also see this article for more.

You need to add a new project. Choose:

Other Languages > Visual C++ > CLR > Class Library

Your code would look like this:

//native C++ CInstrument
//cinstrument.cpp
class CInstrument
{
 ..
}

//this is a CLR class
//Compatible with C#/VB.NET
//cinstrumentwrapper.cpp
ref class CInstumentWrapper
{
 private:
 CInstrument* _instrument;//delegate to the native C++ class
}