1、RabbitMQ.MessageProducer

新建类 ConsumptionACKConfirm

csharp
public static void Show()
{
    var factory = new ConnectionFactory()
    {
        HostName = "localhost",
        UserName = "guest",
        Password = "guest"
    };

    using var connection = factory.CreateConnection();
    using var channel = connection.CreateModel();

    Console.WriteLine("生产者准备就绪");

    channel.QueueDeclare("ConsumptionACKConfirmQueue", true, false, false, null);
    channel.ExchangeDeclare("ConsumptionACKConfirmQueueExchange", ExchangeType.Direct, true, false);
    channel.QueueBind("ConsumptionACKConfirmQueue", "ConsumptionACKConfirmQueueExchange", "ConsumptionACKConfirmKey");

    // 设置优先级
    var props = channel.CreateBasicProperties();

    for (int i = 1; i < 1000; i++)
    {
        props.DeliveryMode = 2;

        string message = $"消息{i}";
        channel.BasicPublish("ConsumptionACKConfirmQueueExchange", "ConsumptionACKConfirmKey", props, Encoding.UTF8.GetBytes(message));

        Thread.Sleep(300);
        Console.WriteLine($"【{message}】 已发送");
    }

}

2、RabbitMQ.MessageConsumer01

新建类 ConsumptionACKConfirm

csharp
public static void Show()
 {
     var factory = new ConnectionFactory()
     {
         HostName = "localhost",
         UserName = "guest",
         Password = "guest"
     };

     using var connection = factory.CreateConnection();
     using var channel = connection.CreateModel();

     #region 定义消费者

     var consumer = new EventingBasicConsumer(channel);

     int i = 0;

     consumer.Received += (model, ea) =>
     {
         var message = Encoding.UTF8.GetString(ea.Body.ToArray());
         //Console.WriteLine($"接受到消息：{message}");

         if (i < 50)
         {
             // 手动确认 消息正常消费，告诉Broker，可以将当前消息删除
             channel.BasicAck(ea.DeliveryTag, false);
             Console.WriteLine(message);
         }
         else
         {
             // 否定，告诉 Broker，消息没有正常消费，重新写入到队列中
             channel.BasicReject(ea.DeliveryTag, true);
         }
         i++;
     };

     Console.WriteLine("消费者准备就绪");
     {
         // 处理消息
         //autoAsk true 自动确认
         //channel.BasicConsume("ConsumptionACKConfirmQueue", true, consumer);
     }
     {
         // 处理消息
         //autoAsk false 手动（显示）确认
         channel.BasicConsume("ConsumptionACKConfirmQueue", false, consumer);
     }

     Console.ReadKey();

     #endregion
 }

3、注意

1、自动消费

BasicConsume 的第二个参数设置为 true，会在初次进入接收消息时，RabbitMQ 网页客户端会清空消息，会将所有消息交由消费端去处理，无法保证消息处理的正确性

2、手动消费

需要将 BasicConsume 的第二个参数设置为 false，使用 channel.BasicAck(ea.DeliveryTag, false) 进行手动确认，若确认失败，使用 channel.BasicReject(ea.DeliveryTag, true) 重新将消息写入队列