cross platform - Callback/Delegate to Java for handling some C# event -

i using c# assembly in java application via jna & unmanaged exports. need implement callback/delegate in order inform java event in c# .dll has occured.

how can accomplished? or there reading reference suggest?

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what tried far: using java native access (jna) & unmanaged exports robert giesecke in order call c# methods java. - works fine far.

i pass callback-method as void* pointer java c#. call method somehow.

for verification added code use:

1. defining jna interface (incl. callback) in java:

   import com.sun.jna.callback; import com.sun.jna.library;     public interface ijna extends library {         interface sig_t extends callback {             boolean invoke(int signal);         }         string testcallback(sig_t callbackparam);     } 

2. unsage c# method exported unmanaged code, receiving "any pointer" (void*) parameter should adress of method

   [dllexport] public unsafe static string testcallback(void* somemethod) {     //use somemethod here     if(somemethod != null)         return "not null"; // somemethod not null when running app     else         return "null"; } 

3. load .dll, define callback function , call in java.

   public static void main(string[] args) {     //load unmanaged .dll     ijna.sig_t referencetofunction = new ijna.sig_t() {         @override             public boolean invoke(int sig) {             system.out.println("signal " + sig + " raised");             return true;         }     };     string test = instance.testcallback(referencetofunction);//returns "not null"     system.out.println(test);  } 

i solve it. using marshal.getdelegateforfunctionpointer(intptr, type) possible convert void* (any pointer) c# delegate.

so c# code adapted following:

    delegate void del(int someint);     del csharpfuncptr; //save delegate, not void* (the void* not preventing gb deleting method, , therefore invalid)     [dllexport]     public unsafe static string testcallback(void* somemethod)     {         intptr method = new intptr(somemethod);         csharpfuncptr = (del)marshal.getdelegateforfunctionpointer(method, typeof(del));         csharpfuncptr(5);     }