一、引言
使用工作队列的一个好处就是它能够并行的处理队列。如果堆积了很多任务，我们只需要添加更多的工作者（workers）就可以了，扩展很简单。本例使用多线程来创建多信道并绑定队列，达到多workers的目的。
二、示例
2.1、环境准备
在NuGet上安装RabbitMQ.Client。
2.2、工厂类
添加一个工厂类RabbitMQFactory：
/// <summary>
/// 多路复用技术(Multiplexing)目的：为了避免创建多个TCP而造成系统资源的浪费和超载，从而有效地利用TCP连接。
/// </summary>
public static class RabbitMQFactory
{
private static IConnection sharedConnection;
private static int ChannelCount { get; set; }
private static readonly object _locker = new object();
public static IConnection SharedConnection
{
get
{
if (ChannelCount >= 1000)
{
if (sharedConnection != null && sharedConnection.IsOpen)
{
sharedConnection.Close();
}
sharedConnection = null;
ChannelCount = 0;
}
if (sharedConnection == null)
{
lock (_locker)
{
if (sharedConnection == null)
{
sharedConnection = GetConnection();
ChannelCount++;
}
}
}
return sharedConnection;
}
}
private static IConnection GetConnection()
{
var factory = new ConnectionFactory
{
HostName = "192.168.2.242",
UserName = "hello",
Password = "world",
Port = AmqpTcpEndpoint.UseDefaultPort,//5672
VirtualHost = ConnectionFactory.DefaultVHost,//使用默认值："/"
Protocol = Protocols.DefaultProtocol,
AutomaticRecoveryEnabled = true
};
return factory.CreateConnection();
}
}2.3、主窗体
代码如下：
public partial class RabbitMQMultithreading : Form
{
public delegate void ListViewDelegate<T>(T obj);
public RabbitMQMultithreading()
{
InitializeComponent();
}
/// <summary>
/// ShowMessage重载
/// </summary>
/// <param name="msg"></param>
private void ShowMessage(string msg)
{
if (InvokeRequired)
{
BeginInvoke(new ListViewDelegate<string>(ShowMessage), msg);
}
else
{
ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), msg });
lvwMsg.Items.Insert(0, item);
}
}
/// <summary>
/// ShowMessage重载
/// </summary>
/// <param name="format"></param>
/// <param name="args"></param>
private void ShowMessage(string format, params object[] args)
{
if (InvokeRequired)
{
BeginInvoke(new MethodInvoker(delegate ()
{
ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), string.Format(format, args) });
lvwMsg.Items.Insert(0, item);
}));
}
else
{
ListViewItem item = new ListViewItem(new string[] { DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss ffffff"), string.Format(format, args) });
lvwMsg.Items.Insert(0, item);
}
}
/// <summary>
/// 生产者
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSend_Click(object sender, EventArgs e)
{
int messageCount = 100;
var factory = new ConnectionFactory
{
HostName = "192.168.2.242",
UserName = "hello",
Password = "world",
Port = AmqpTcpEndpoint.UseDefaultPort,//5672
VirtualHost = ConnectionFactory.DefaultVHost,//使用默认值："/"
Protocol = Protocols.DefaultProtocol,
AutomaticRecoveryEnabled = true
};
using (var connection = factory.CreateConnection())
{
using (var channel = connection.CreateModel())
{
channel.QueueDeclare(queue: "hello", durable: true, exclusive: false, autoDelete: false, arguments: null);
string message = "Hello World";
var body = Encoding.UTF8.GetBytes(message);
for (int i = 1; i <= messageCount; i++)
{
channel.BasicPublish(exchange: "", routingKey: "hello", basicProperties: null, body: body);
ShowMessage($"Send {message}");
}
}
}
}
/// <summary>
/// 消费者
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void btnReceive_Click(object sender, EventArgs e)
{
Random random = new Random();
int rallyNumber = random.Next(1, 1000);
int channelCount = 0;
await Task.Run(() =>
{
try
{
int asyncCount = 10;
List<Task<bool>> tasks = new List<Task<bool>>();
var connection = RabbitMQFactory.SharedConnection;
for (int i = 1; i <= asyncCount; i++)
{
tasks.Add(Task.Factory.StartNew(() => MessageWorkItemCallback(connection, rallyNumber)));
}
Task.WaitAll(tasks.ToArray());
string syncResultMsg = $"集结号 {rallyNumber} 已吹起号角--" +
$"本次开启信道成功数:{tasks.Count(s => s.Result == true)}，" +
$"本次开启信道失败数:{tasks.Count() - tasks.Count(s => s.Result == true)}" +
$"累计开启信道成功数：{channelCount + tasks.Count(s => s.Result == true)}";
ShowMessage(syncResultMsg);
}
catch (Exception ex)
{
ShowMessage($"集结号 {rallyNumber} 消费异常：{ex.Message}");
}
});
}
/// <summary>
/// 异步方法
/// </summary>
/// <param name="state"></param>
/// <param name="rallyNumber"></param>
/// <returns></returns>
private bool MessageWorkItemCallback(object state, int rallyNumber)
{
bool syncResult = false;
IModel channel = null;
try
{
IConnection connection = state as IConnection;
//不能使用using (channel = connection.CreateModel())来创建信道，让RabbitMQ自动回收channel。
channel = connection.CreateModel();
channel.QueueDeclare(queue: "hello", durable: true, exclusive: false, autoDelete: false, arguments: null);
channel.BasicQos(prefetchSize: 0, prefetchCount: 1, global: false);
var consumer = new EventingBasicConsumer(channel);
consumer.Received += (model, ea) =>
{
var message = Encoding.UTF8.GetString(ea.Body);
Thread.Sleep(1000);
ShowMessage($"集结号 {rallyNumber} Received {message}");
channel.BasicAck(deliveryTag: ea.DeliveryTag, multiple: false);
};
channel.BasicConsume(queue: "hello", autoAck: false, consumer: consumer);
syncResult = true;
}
catch (Exception ex)
{
syncResult = false;
ShowMessage(ex.Message);
}
return syncResult;
}
}2.4、运行结果
多点几次消费者即可增加信道，提升消费能力。
来源：oschina
链接：https://my.oschina.net/u/4330928/blog/3236277