I've seen a few newsgroups with SSIS developers having difficulties enlisting in the active transaction with a custom Data Flow component in .NET. I recently had to do this to enable message queue operations to be performed within the active transaction for the package. Unfortunately the built in Message Queue task has no support for enlisting in the active transaction so a custom approach was required. I'm sure that most SSIS developers who have dabbled with custom components will have seen the following Microsoft.SqlServer.Dts.Pipeline.PipelineComponent class:

            
              ///
<summary>
              ///
Establishes a connection to a connection manager
              ///
</summary>
              public
              virtual
              void AcquireConnections
(object transaction)
          

          
            ///
<summary>
            ///
Get a <code>System.Transactions.Transaction</code> from a supplied COM
transaction pointer
            ///
</summary>
            public
            static Transaction
GetTransactionFromCom(object comTransaction)
{     Transaction managedTransaction =null;
    ITransaction transactionInterface = comTransaction as ITransaction;
    if (transactionInterface
!=null)
    {         managedTransaction =             TransactionInterop.GetTransactionFromDtcTransaction((IDtcTransaction)transactionInterface);
    }     return managedTransaction;
}
        

Once the supplied COM transaction pointer has been converted to a managed Transaction object it can be used as normal with your .NET code. For message queue transactions this means setting the ambient transaction and sending/receiving messages using MessageQueueTransactionType.Automatic. For example:

            
              //
Save the current transaction Transaction previousTransaction = Transaction.Current; //
Set the current ambient transaction Transaction.Current = managedTransaction; try {
    using (MessageQueue
queue =new MessageQueue(messageQueuePath))
    {         queue.Send("Body", "Label",
MessageQueueTransactionType.Automatic);     } } finally {
    Transaction.Current = previousTransaction;
}
          

I recently needed to access the Label property of a remote private MSMQ through .NET. Naturally my first thought was that this should be a pretty trivial operation as this property is exposed via the MessageQueue (System.Messaging) class in the .NET framework. Unfortunately however, this property can only be read for local private queues (those on the same machine as the executing code) not for remote private queues. According to Microsoft "Private queues are registered on the local computer, not in the directory service, and their properties cannot be obtained by Message Queuing applications running on remote computers".

After a bit of testing, I found that it is possible to access remote private queue properties through .NET using DCOM. The following example shows how this can be achieved for the Label property. The same technique can be applied to retrieve other queue properties such as the Transactional state of the queue.

          
            public
            static
            string GetRemoteQueueLabel(MessageQueue
queue, string serverAddress)
{     //
Find label for remote private queue     object queueInfoDcom = Activator.CreateInstance(Type.GetTypeFromProgID("MSMQ.MSMQQueueInfo",
serverAdress));     Type classType = queueInfoDcom.GetType();
    //
Invoke method using reflection and return outputs     BindingFlags
bindingFlags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.SetProperty;
    classType.InvokeMember("FormatName",
bindingFlags, null,
queueInfoDcom, newobject[]
{ queue.FormatName });     bindingFlags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod;
    classType.InvokeMember("Refresh",
bindingFlags, null,
queueInfoDcom, newobject[]
{ });     bindingFlags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.GetProperty;
    string label = (string)classType.InvokeMember("Label",
bindingFlags, null,
queueInfoDcom, newobject[]
{ });     return label;
}