How to Create a C# Listener Service for MSMQ as a Windows Service

Question

I'll start by saying I'm not a .NET developer, but have been thrown into a project where I need to use MSMQ so a classic ASP web application can send messages to a C# Windows Service that handles the processing. I have experience integrating other message queues with other languages, but like I mentioned, I don't have much experience with .NET and Windows development so some guidance would be much appreciated.

Here are my questions...

1. Could someone provide some basic C# code that listens to an existing MSMQ queue and responds to the new message by doing something simple like writing the current timestamp to a log file or sending an email?

2. How do I package this code up in Visual Studio .NET to create and install a Windows Service? (What type of project should it be, etc. I'm using Visual C# 2010 Express.)

3. Finally, I'm not sure which version and/or implementation of MSMQ I need to be using for my requirements with classic ASP. I think the COM version is what I need, but I've also read about a new WCF version, as well as differences between 3.0 and 4.0. Could someone please give me direction on which version I should be using?

Many thanks!

Answer 1

You can wait for a message on a given queue using the following code (You want to use the private queue named SomeQueue on your computer, named ComputerName => QueueName = @"ComputerName\private$\SomeQueue")

    public void AsyncWatchQueue(object encapsulatedQueueName)
    {
        Message newMessage;
        MessageQueue queue;

        string queueName = encapsulatedQueueName as string;
        if (queueName == null)
            return;

        try
        {
            if (!MessageQueue.Exists(queueName))
                MessageQueue.Create(queueName);
            else
            {
                queue = new MessageQueue(queueName);

                if (queue.CanRead)
                    newMessage = queue.Receive();
            }
            HandleNewMessage(newMessage); // Do something with the message
        }
        // This exception is raised when the Abort method 
        // (in the thread's instance) is called
        catch (ThreadAbortException e) 
        {
            //Do thread shutdown
        }
        finally
        {
            queue.Dispose();
        }
    }

Note: the Receove method will block untill a message is received at which point it'll remove the message from the queue and return it.

edit: added code for the implementation of the multithreaded portion (and renamed the above method signature)

Thread Creation Code:

        public Thread AddWatchingThread(string QueueName)
    {
        Thread Watcher = 
            new Thread(new ParameterizedThreadStart(AsyncWatchQueue));
        Watcher.Start(QueueName);
        // The thread instance is used to manipulate (or shutdown the thread)
        return Watcher; 
    }

I'll just note, that this is untested cod, it's just an quick example