RabbitMQ 消费者

原文连接：https://www.cnblogs.com/ysmc/p/16225142.html

项目需要引用 RabbitMQ.Client Nuget包

创建异步工厂

IAsyncConnectionFactory connectionFactory = new ConnectionFactory
{
    HostName = _rabbitMqOptions.HostName,
    Port = _rabbitMqOptions.Port,
    UserName = _rabbitMqOptions.UserName,
    Password = _rabbitMqOptions.Password,
    VirtualHost = _rabbitMqOptions.VirtualHost,
    DispatchConsumersAsync = true
};

订阅

//创建连接
var connection = connectionFactory.CreateConnection();
//创建通道
var channel = connection.CreateModel();
channel.BasicQos(prefetchSize, prefetchCount, false);
//事件基本消费者
var consumer = new AsyncEventingBasicConsumer(channel);
//接收到消息事件
consumer.Received += async (ch, ea) =>
{
    try
    {
        var message = Encoding.UTF8.GetString(ea.Body.ToArray());
        var requeue = await executeAsync(message);
        if (requeue)
        {
            //确认该消息已被消费
            channel.BasicAck(ea.DeliveryTag, false);
        }
        else
        {
            channel.BasicNack(ea.DeliveryTag, false, true);
        }
    }
    catch (Exception)
    {
        channel.BasicAck(ea.DeliveryTag, false);
    }
};
//启动消费者 设置为手动应答消息
channel.BasicConsume(queueName, false, consumer);

单次或轮询

private async Task SingleOrPolling(Func<string, Task<bool>> executeAsync, bool isSingle, string? queueName = null)
{
    var connectionFactory = _rabbitMQBaseService.GetAsyncConnectionFactory();
    using var connection = connectionFactory.CreateConnection();
    using var channel = connection.CreateModel();
    queueName = GetQueueName(queueName);
    while (true)
    {
        var response = channel.BasicGet(queueName, false);
        try
        {
            if (null != response)
            {
                var message = Encoding.UTF8.GetString(response.Body.ToArray());
                var requeue = await executeAsync(message);
                if (requeue)
                {
                    //确认该消息已被消费
                    channel.BasicAck(response.DeliveryTag, false);
                }
                else
                {
                    channel.BasicNack(response.DeliveryTag, false, true);
                }
            }
        }
        catch (Exception)
        {
            channel.BasicAck(response.DeliveryTag, false);
        }
        if (isSingle)
        {
            break;
        }
    }
}