working with unmanaged C++

[codeinthedark]

I'm hoping someone will be able to help me with an issue relating to working with unmanaged C++.

I've been able to get most things working with regard to mapping from unmanaged C++ to C#, but the area I'm having a problem with is with a C++ callback to a C# delegate. The delegate is being called and executing, but when the delegate ends and sends the return code to C++, I'm getting a Windows error. Nothing is being returned to the managed debugger and the app just dies.

I would really appreciate any help that could be provided. The following is what I've been working with. Thanks.

3-d Party C++:
_declspec(dllexport)  ULONG   NIrtd_startDataStream( 
                                            NIrtd_tAPIauth    *authorization,
                                            NIrtd_tQuery        *query,
                                            ULONG                updateRate,
                                            NIrtd_funCallback    callback,
                                            void               *yourpointer,
                                            NIrtd_tRequestId    *requestId);
 
/* Call back routine definition */
typedef  ULONG (* NIrtd_funCallback) (
                                     ULONG      return_code,
                                     NIrtd_tRequestId        requestid,
                                     NIrtd_stTableGroup *    tableGroup,
                                     void *  yourpointer);
 
 
C++ Wrapper:
extern "C" __declspec(dllimport)  ULONG NIrtd_startDataStream_CLib(
        AuthInfo_CLib        *authInfoStruct,
        Query_CLib            *queryStruct,
        ULONG                  updateRate,
        NIrtd_funCallback   callback,
        AppPtr_CLib          *appPtr,
        Request_CLib         *requestStruct
);
 
 
C#:
 public delegate uint RealTimeCallBack(uint return_code,
        IntPtr requestId,
        ref TableGroupStruct tableGroup,
        ref IntPtr appPtr);
 
 private static RealTimeCallBack _RealTimeCallBack = null;
 
 private uint RealTimeCallBackHandler(uint return_code,
        IntPtr requestId,
        ref TableGroupStruct tableGroupStruct,
        ref IntPtr appPtr)
        {
            try
            {
                Console.WriteLine("server: Callback handler called");
             }
            catch(Exception ex)
            {
                throw new Exception("RealTimeCallBackHandler: " + 
                ex.ToString() );
            }
 
            return 0;
        }
 
[DllImport("RtdApi.dll")]
public static extern uint NIrtd_startDataStream_CLib(
            ref AuthInfo authInfo,
            ref Query query,
            uint updateRate,
            RealTimeCallBack callback,
            ref AppPtr appPtr,
            ref Request request);

As mentioned, the startDataStream_CLib is setting things up properly and the delegate is being fired, but it's after the delegate ends (after the closing brace) that the app dies.

Any ideas?

Thanks.

Juan

[kenobewan]

It appears as though the problem you are having is with C++. Would you like me to move your question to the C++ forum, where you are more likely to receive expert help with C++?