channel.ExchangeDeclare("logs", ExchangeType.Fanout);

Fanout类型它只是将接收到的所有消息广播到它知道的所有队列中

using RabbitMQ.Client;
using System;
using System.Text;
namespace EmitLog
{
    class Program
    {
        static void Main(string[] args)
        {
            var factory = new ConnectionFactory()
            {
                HostName = "localhost"
            };
            using (var connection = factory.CreateConnection())
            {
                using (var channel = connection.CreateModel())
                {
                    channel.ExchangeDeclare(exchange: "logs", type: ExchangeType.Fanout);//声明   Fanout 将消息推送到他知道的所有队列
                    var message = GetMessage(args);
                    var body = Encoding.UTF8.GetBytes(message);
                    channel.BasicPublish(exchange: "logs", routingKey: "", basicProperties: null, body: body);//发布
                    Console.WriteLine(" [x] Sent {0}", message);
                }
                Console.WriteLine(" Press [enter] to exit.");
                Console.ReadLine();
            }
        }
        private static string GetMessage(string[] args)
        {
            return args.Length > 0 ? string.Join(" ", args) : "info: Hello World!";
        }
    }
}

接收者代码:

using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using System;
using System.Text;
namespace ReceiveLogs
{
    class Program
    {
        static void Main(string[] args)
        {
            var factory = new ConnectionFactory()
            {
                HostName = "localhost"
            };
            using (var connection = factory.CreateConnection())
            {
                using (var channel = connection.CreateModel())
                {
                    channel.ExchangeDeclare(exchange: "logs", type: ExchangeType.Fanout);//声明订阅
                    var queueName = channel.QueueDeclare().QueueName;
                    channel.QueueBind(queue: queueName, exchange: "logs", routingKey: "");
                    Console.WriteLine(" [*] Waiting for logs.");
                    var consumer = new EventingBasicConsumer(channel);
                    consumer.Received += (model, ea) =>
                    {
                        var body = ea.Body.ToArray();
                        var message = Encoding.UTF8.GetString(body);
                        Console.WriteLine(" [x] {0}", message);
                    };
                    channel.BasicConsume(queue: queueName,autoAck: true,consumer: consumer);
                    Console.WriteLine(" Press [enter] to exit.");
                    Console.ReadLine();
                }
            }
        }
    }
}

开启多个接收者,发布消息时，他们都会收到同样的信息

发布/订阅