一般情况下，生产者发送消息，先到先得，一个消费者消费之后，该条消息便消失不会再被消费，抢完即止。
那能否生产者发送的消息每个消费者都能接收到，都能消费呢？
Fanout交换机就可以实现。
代码实现：
生产者：
public class FanoutExchange { public void FanoutPublish() { MQHelper mh = new MQHelper(); using (var conn = mh.GetConnection()) { using (IModel channel = conn.CreateModel()) { //声明队列 channel.QueueDeclare(queue: "FanoutAdu001", durable: true, exclusive: false, autoDelete: false, arguments: null); channel.QueueDeclare(queue: "FanoutAdu002", durable: true, exclusive: false, autoDelete: false, arguments: null); //声明交换机 channel.ExchangeDeclare(exchange: "FanoutExchange", type: ExchangeType.Fanout, durable: true, autoDelete: false, arguments: null); //绑定 channel.QueueBind(queue: "FanoutAdu001", exchange: "FanoutExchange", routingKey: string.Empty,arguments:null); channel.QueueBind(queue: "FanoutAdu002", exchange: "FanoutExchange", routingKey: string.Empty, arguments: null); //发布 int i = 0; while (true) { string message = $"通知{i}"; var body = Encoding.UTF8.GetBytes(message); channel.BasicPublish(exchange: "FanoutExchange", routingKey: string.Empty, basicProperties: null, body: body); Console.WriteLine($"通知{i}已发送到队列"); Thread.Sleep(2000); i++; } } } } }
可以看到，这里和Direct交换机代码相比，类型发生了变化，同时路由键变成了Empty
消费者：
public class FanoutExchangeConsumer { public void FanoutConsume() { var factory = new ConnectionFactory(); factory.HostName = "localhost"; factory.UserName = "guest"; factory.Password = "guest"; using (var conn = factory.CreateConnection()) { using (IModel channel = conn.CreateModel()) { //声明队列 channel.QueueDeclare(queue: "FanoutAdu002", durable: true, exclusive: false, autoDelete: false, arguments: null); //声明交换机 channel.ExchangeDeclare(exchange: "FanoutExchange", type: ExchangeType.Fanout, durable: true, autoDelete: false, arguments: null); //绑定 channel.QueueBind(queue: "FanoutAdu002", exchange: "FanoutExchange", routingKey: string.Empty); //消费消息 var consumer = new EventingBasicConsumer(channel); consumer.Received += (model, ea) => { var body = ea.Body; var message = Encoding.UTF8.GetString(body.ToArray()); Console.WriteLine($"接收成功，[{message}]"); }; //处理消息 channel.BasicConsume(queue: "FanoutAdu002", autoAck: true, consumer: consumer); } } } }
这里每个消费者一条路由，都能够接收生产者发送的所有消息