Submitting C++ callback to .NET C++/CLI Wrapper -

i've been searching web solution following problem cannot head around it.

we have big monolithic application med in c++. "upgrade" new world embed wpf views in generated in c++/cli managed wrapper. initial call made c++ via smartpointer.

        if (succeeded(ptr.createinstance(__uuidof(cloudservices))))     {         crect rect;         pwndcontainer->getwindowrect(rect);          ptr->initializecontrol((long)pwndcontainer->getsafehwnd(), id_ais_balancematrix, bstr.m_str, rect.width(), rect.height());     } 

and in wrapper class interface declared like

interface icloudservices : idispatch{ [id(1)] hresult initializecontrol([in] long hwndparent, [in] long controltypeid, [in] bstr parameters, [in] long width, [in] long height); 

and implemented in wrapper

stdmethodimp ccloudservices::initializecontrol(long hwndparent, long controltypeid, bstr parameters, long width, long height) { ... } 

problem: works fine , wpf view rendered within c++ app. need send information c++ .net code.

how can submit unmanaged callback function wrapper argument initializecontrol , how use/convert relevant .net delegate?

see desired solution schematic

we did not seem find working solution problem ended sending information using wm_datacompy. not effecient way works.

    public void sendcommand(command command)     {         // find target window handle.         intptr htargetwnd = nativemethod.findwindow("ourappnameincpp", null);         if (htargetwnd == intptr.zero)         {             throw new exception("sending '{0}'. unable find \"ourappnameincpp\" window".args(command.asxmlmessage));         }          // prepare copydatastruct struct data sent.         mystruct mystruct;          mystruct.message = command.asxmlmessage;          // marshal managed struct native block of memory.         int mystructsize = marshal.sizeof(mystruct);         intptr pmystruct = marshal.allochglobal(mystructsize);         try         {             marshal.structuretoptr(mystruct, pmystruct, true);              copydatastruct cds = new copydatastruct();             cds.cbdata = mystruct.message.length + 1;             cds.lpdata = marshal.stringtohglobalansi(mystruct.message);              // send copydatastruct struct through wm_copydata message              // receiving window. (the application must use sendmessage,              // instead of postmessage send wm_copydata because receiving              // application must accept while guaranteed valid.)             nativemethod.sendmessage(htargetwnd, wm_copydata, intptr.zero, ref cds);              int result = marshal.getlastwin32error();             if (result != 0)                 throw new exception("sendmessage(wm_copydata) failed w/err 0x{0:x}".args(result));         }                 {             marshal.freehglobal(pmystruct);         }     }