NCo 3 RfcServer: TransactionID in called function always NULL

Question

Hello,
using NCo 3 (v3.0.1, x64) I wrote a RfcServer which receives IDocs via the function "IDOC_INBOUND_ASYNCHRONOUS". When the function is called by SAP the  TransactionIDHandler seems to work fine as these functions are called together with a TransactionID (CheckTransactionID, Rollback, ConfirmTransactionID). But if my implemented function itself is called it never belongs to the Transaction (RfcServerContext.TransactionID == NULL and RfcServerContext.InTransaction == false).
Execution sequence:
- Check transaction (with ID)
- IDOC_INBOUND_ASYNCHRONOUS (without TransactionID)
- Rollback transaction (with ID)
- Confirm transaction (with ID)
As I'm new to the NCo I wonder if this is the correct behaviour. I expect to get the transaction ID passed into the function call. Otherwise I don't know which transaction the function call belongs to. Any help appreciated.
Thanks,
Mathias
    Type[] handlers = new Type[1] { typeof(RFC_Server_Handler) };
    RfcServer server = RfcServerManager.GetServer("DEV", handlers);
    server.RfcServerError += OnRfcServerError;
    server.RfcServerApplicationError += OnRfcServerError;
    server.RfcServerStateChanged += OnRfcServerStateChanged;
    server.TransactionIDHandler = new RFC_Transaction_Handler();
    server.Start();
[RfcServerFunction(Name = "IDOC_INBOUND_ASYNCHRONOUS", Default = false)]
public void IDOC_INBOUND_ASYNCHRONOUS(RfcServerContext context, IRfcFunction function) {
    //context.TransactionID is null
    //context.InTransaction is false

Answer 1

Hello Mathias;
I wonder how the implementation of server.TransactionIDHandler RFC_Transaction_Handler = new ();
Thank you!