收到没有被触发

Question

我将共享库作为总线，我正在尝试从 rabbitmq 接收消息，但 ConsumerOnReceived 从未被触发。

namespace Bus
{
    public class MessageListener
    {

    private static IConnection _connection;
    private static IModel _channel;

    public void Start(string hostName, int port, string queueName)
    {
        var factory = new ConnectionFactory() { HostName = hostName, Port = port };
        using (var connection = factory.CreateConnection())
        using (var channel = connection.CreateModel())
        {
            channel.QueueDeclare(queue: queueName,
                                 durable: false,
                                 exclusive: false,
                                 autoDelete: false,
                                 arguments: null);

            var consumer = new EventingBasicConsumer(channel);
            consumer.Received += ConsumerOnReceived;

            channel.BasicConsume(queue: queueName,
                                 noAck: true,
                                 consumer: consumer);
        }
    }

    public static void Stop()
    {
        _channel.Close(200, "Goodbye");
        _connection.Close();
    }

    public virtual void ConsumerOnReceived(object sender, BasicDeliverEventArgs ea)
    {
        var body = ea.Body;
        var message = Encoding.UTF8.GetString(body);
    }
}

public static class MessageSender
{
    public static void Send(string hostName, int port, string queueName, string message)
    {
        var factory = new ConnectionFactory() { HostName = hostName, Port = port };
        using (var connection = factory.CreateConnection())
        using (var channel = connection.CreateModel())
        {
            channel.QueueDeclare(queue: queueName, durable: false, exclusive: false, autoDelete: false, arguments: null);

            var body = Encoding.UTF8.GetBytes(message.ToString());

            channel.BasicPublish(exchange: "", routingKey: queueName, basicProperties: null, body: body);
        }
    }
}

}

核心

namespace Core
{
    class Program
    {
        static void Main(string[] args)
        {
            new MessageListener().Start("localhost", 5672, "MakePayment");

            Console.WriteLine("Core Service");
            string line = Console.ReadLine();
        }

    }
}

namespace Core
{
    public class MessageListener : Bus.MessageListener
    {
        public override void ConsumerOnReceived(object sender, BasicDeliverEventArgs ea)
        {
            var body = ea.Body;
            var message = Encoding.UTF8.GetString(body);
        }
    }

}

Answer 1

问题来了

channel.BasicConsume(queue: queueName, noAck: true, consumer: consumer);

但是，BasicConsume 不是阻塞方法，因此当您调用 Start 时，您会创建一个连接和一个通道，但它会立即被释放。

以下是不是解决方案，但您可以通过执行以下操作来确认：

channel.BasicConsume(queue: queueName, noAck: true, consumer: consumer);
Console.ReadKey();//←Added Line

您的程序将以这种方式运行。

这是我提出的解决方案。请注意_channel.BasicConsume(queue: queueName, noAck: true, consumer: consumer); 将在另一个线程上启动，因此您不需要使用while(...)

using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using RabbitMQ.Client;
using RabbitMQ.Client.Events;

namespace Bus {

    public abstract class BaseMessageListener {
        private static IModel _channel;
        private static IConnection _connection;

        public abstract void ConsumerOnReceived(object sender, BasicDeliverEventArgs ea);

        public void Start(string hostName, int port, string queueName) {
            var factory = new ConnectionFactory() { HostName = hostName, Port = port };
            _connection = factory.CreateConnection();
            _channel = _connection.CreateModel();
            _channel.QueueDeclare(queue: queueName, durable: false, exclusive: false, autoDelete: false);
            var consumer = new EventingBasicConsumer(_channel);
            consumer.Received += ConsumerOnReceived;
            _channel.BasicConsume(queue: queueName, noAck: true, consumer: consumer);//This will start another thread!
        }

        public void Stop() {
            _channel.Close(200, "Goodbye");
            _connection.Close();
        }
    }
}

namespace StackOverfFLow.RabbitMQSolution {

    using Bus;

    public class MessageListener : BaseMessageListener {

        public override void ConsumerOnReceived(object sender, BasicDeliverEventArgs ea) {
            var body = ea.Body;
            var message = Encoding.UTF8.GetString(body);
            Console.WriteLine(message);
        }
    }

    internal class Program {

        private static void Main(string[] args) {
            var listener = new MessageListener();
            listener.Start("localhost", 5672, "MakePayment");
            Console.WriteLine("Core Service Started!");
            Console.ReadKey();
            listener.Stop();
        }
    }
}