Invoking a clr event from a non-clr library

[Monkeyfun]

Hi,

I have a CAN controller from which I need to read packets whenever one is received. With the CAN controller came a WIN32 (non clr) library. When a CAN packet is received the library must trigger an event, which will read the data and process it.

The library takes a __stdcall function pointer, which it uses to make a callback. The callback must be made into my clr class, in which the incomming is processed.

Is it possible to create a clr environment that can interface with a standard WIN32 library in a interrupt style way?

My function is CCAN::ReadBusEv ent and I have tried to play around with delegates but since I am not that familiar with this, I have not been able to create anything that compiles.

I keep running into problems such as:

error C2664: 'CANPC_set_interrupt_event' : cannot convert parameter 1 from 'MyDel ^' to 'HANDLE'
 
error C3374: can't take address of 'CCAN::ReadBusEvent' unless creating delegate instance

(HANDLE is a function pointer)

I am new to clr and VS 2005, so I don't know that best way to go about it. I don't have any code to show, so I am only asking about ideas on how to program this solution.

/Christian

PS. Old WIN32 implementation:

/**********************************************************
  Initialize interrupt handling
**********************************************************/
int InitInterruptHandling32(void)
{
  int ret;
 
  if (NULL == (threadData.events[INT_EVENT] = CreateEvent(NULL, FALSE, FALSE, NULL)))
  {
//    printf("-->Error creating interrupt event 0x%X\n", GetLastError());
    return(-1);
  }
 
  ResetEvent(threadData.events[INT_EVENT]);
 
  if (NULL == (threadData.events[END_EVENT] = CreateEvent(NULL, FALSE, FALSE, NULL)))
  {
//    printf("-->Error creating thread end event 0x%X\n", GetLastError());
    CloseHandle(threadData.events[INT_EVENT]);
    return(-1);
  }
 
  if (CANPC_OK != (ret = CANPC_set_interrupt_event(threadData.events[INT_EVENT])))
  {
//    printf("-->Error set interrupt event 0x%X\n", ret);
    CloseHandle(threadData.events[INT_EVENT]);
    CloseHandle(threadData.events[END_EVENT]);
    return(-1);
  }
 
 
  if (NULL == (intThread = (HANDLE) _beginthreadex(NULL, 0, interruptThread, 
                                                   (void *) &threadData, 0, &tid)))
  {
//    printf("-->Error create interrupt thread 0x%X\n", GetLastError());
    INIPC_close_board();
    CloseHandle(threadData.events[INT_EVENT]);
    CloseHandle(threadData.events[END_EVENT]);
    return(-1);
  }
 
  InitializeCriticalSection(&CriticalSectionForInterrupt);
 
  return(0);
}

[weaknessforcats]

I presume you have entered unmanaged code? Yes?

[AdrianH]

It seems clear to me that threadData.even ts[INT_EVENT] is not of the right type.

It also appears to be a C# type.

IIRC, you will need some type of wrapper to allow the C# to interact directly with the Win32 API.


Adrian

[weaknessforcats]

you will need some type of wrapper to allow the C# to interact directly with the Win32 API.

I think in C# you use the SecurityPermiss ion object ndrequest access to umanaged code by s settting of the SecurityPermiss ionFlag. Once you have permission, you can call native Win32 functions using C++.

Checout all of the Ineroperability doeumentation provided for C# in Visual Studio.NET.