CloudAMQP with .NET Getting started

The RabbitMQ .NET client is an implementation of an AMQP client library for C# (and, implicitly, other .NET languages).

The RabbitMQ .NET client is maintained by RabbitMQ and can be included in your project as a package using the NuGet package manager.

First of all we need to connect to the server. Add the namespace RabbitMQ.Client to your file and create a ConnectionFactory Set the URI to the CloudAMQP url. The URL can be found in the control panel details for your instance.

Code example

Publish

..
using RabbitMQ.Client;

// CloudAMQP URL in format amqp://user:pass@hostName:port/vhost
private static readonly string _url = "amqp://guest:guest@localhost/%2f";

// Create a ConnectionFactory and set the Uri to the CloudAMQP url
// the connectionfactory is stateless and can safetly be a static resource in your app
var factory = new ConnectionFactory
{
    Uri = new Uri(url)
};
// create a connection and open a channel, dispose them when done
using var connection = factory.CreateConnection();
using var channel = connection.CreateModel();
// ensure that the queue exists before we publish to it
var queueName = "queue1";
bool durable = false;
bool exclusive = false;
bool autoDelete = true;

channel.QueueDeclare(queueName, durable, exclusive, autoDelete, null);

// read message from input
var message = Console.ReadLine();
// the data put on the queue must be a byte array
var data = Encoding.UTF8.GetBytes(message);
// publish to the "default exchange", with the queue name as the routing key
var exchangeName = "";
var routingKey = queueName;
channel.BasicPublish(exchangeName, routingKey, null, data);

Subscribe

..
using RabbitMQ.Client;
using RabbitMQ.Client.Events;

public class Consumer
{
  private IConnection _connection;
  private IModel _channel;
  private ManualResetEvent _resetEvent = new ManualResetEvent(false);

  public void ConsumeQueue()
  {
    // CloudAMQP URL in format amqp://user:pass@hostName:port/vhost
    string _url = "amqp://guest:guest@localhost/%2f";
    // create a connection and open a channel, dispose them when done
    var factory = new ConnectionFactory
    {
        Uri = new Uri(url)
    };

    _connection = factory.CreateConnection();
    _channel = _connection.CreateModel();

    // ensure that the queue exists before we access it
    var queueName = "queue1";
    bool durable = false;
    bool exclusive = false;
    bool autoDelete = true;

    _channel.QueueDeclare(queueName, durable, exclusive, autoDelete, null);

    var consumer = new EventingBasicConsumer(_channel);

    // add the message receive event
    consumer.Received += (model, deliveryEventArgs) =>
    {
        var body = deliveryEventArgs.Body.ToArray();
        // convert the message back from byte[] to a string
        var message = Encoding.UTF8.GetString(body);
        Console.WriteLine("** Received message: {0} by Consumer thread **", message);
        // ack the message, ie. confirm that we have processed it
        // otherwise it will be requeued a bit later
        _channel.BasicAck(deliveryEventArgs.DeliveryTag, false);
    };

    // start consuming
    _ = _channel.BasicConsume(consumer, queueName);
    // Wait for the reset event and clean up when it triggers
    _resetEvent.WaitOne();
    _channel?.Close();
    _channel = null;
    _connection?.Close();
    _connection = null;
  }
}

The full .NET C# code can be seen at https://github.com/cloudamqp/dotnetcore-amqp-example.

.NET Further reading

RabbitMQ .NET tutorial

"Hello World" example from RabbitMQ