How to pass a JNI C# class into Java or handle this situation?

Question

I'm trying to call a Java method from C#, it's called like this from java:

EgamePay.pay(thisActivity, payAlias, new EgamePayListener() {
            @Override
            public void paySuccess(String alias) {
            }

            @Override
            public void payFailed(String alias, int errorInt) {
            }

            @Override
            public void payCancel(String alias) {
            }
        });

The first two parameters are ok, but how do I pass the EgamePayListner through in C#? Simply creating a C# class with the same functions won't work...

Here's what I'm doing currently:

using (AndroidJavaClass jc = new AndroidJavaClass("cn.egame.terminal.smspay.EgamePay"))
        {
            System.IntPtr cls_Activity = AndroidJNI.FindClass("com/unity3d/player/UnityPlayer");
            System.IntPtr fid_Activity = AndroidJNI.GetStaticFieldID(cls_Activity, "currentActivity", "Landroid/app/Activity;");
            object[] p = { fid_Activity, "payAlias", new EgamePayListener() };
            jc.CallStatic("pay", p);
        }

..

 class EgamePayListener
    {
        public void paySucess(string alias)
        {
        }

        public void payFailed(string alians, int errorInt)
        {
        }

        public void payCancel(string alias)
        {
        }
    }

Obviously that's wrong, how can I handle this situation so that I can get notified back in C# land when those functions are fired?

Answer 1

You can link these projects together in VS201X via references. From here, you should be able to fill in the other layers(JNI/Java), and then start passing your pointers(as a long) around the system and invoking your functions.

C# Layer

Program.cs

namespace CSharpLayer
{
class Program : CLILayer.CLIObject
{
    static void Main(string[] args)
    {
        Program p = new Program();

        p.invokeJava();
    }

    public void invokeJava()
    {
        //Call into CLI layer function to loadJVM, call Java code, etc
        loadJava();
    }

    public override void callback(string data)
    {
        //This will be called from the CLI Layer.
    }

}
}

C++/CLI Layer - DLL C++ project w/ CLR support(/clr)

CLIObject.h

#pragma once

namespace CLILayer
{
public ref class CLIObject
{
    public:
        CLIObject();
        ~CLIObject();

        void loadJava(System::String^ jvm, System::String^ classpath);

        virtual void callback(System::String^ data) = 0;
};
}

CLIObject.cpp

#include "CLIObject.h"
#include <string>

#include <msclr/marshal_cppstd.h>
#include <msclr/marshal.h>

using namespace msclr::interop;
using namespace CLILayer;

CLIObject::CLIObject()
{   
}

CLIObject::~CLIObject()
{
}
CLIObject::loadJava(System::String^ jvmLocaion, System::String^ classpath)
{
    std::string _jvmLoc = marshal_as<std::string>(jvmLocation);
    std::string _classpath = marshal_as<std::string>(classpath);
}