.NET消息队列的使用

在项目中使用消息队列，可以对消息提供方和消息消费方进行解耦，提高系统的灵活性和可拓展性。其中，企业级的消息队列中间件有IBM WebSphere MQ、Tibco EMS、HornetQ等等。微软的Windows系统也自带了消息队列的功能，可以在“启动或关闭Windows功能”中开启：

开启后在服务中查看消息队列服务是否运行：

接下来是简单的消息队列操作：

    using System;
    using System.Messaging;

    namespace MQ
    {
        class MQHelper
        {
            /// <summary>
            /// 创建一个消息队列
            /// </summary>
            /// <param name="name">消息队列的名称</param>
            /// <returns>是否创建成功</returns>
            public static bool CreateNewMQ(string name)
            {
                if (!MessageQueue.Exists(".\\private$\\" + name))
                {

                    MessageQueue mq = MessageQueue.Create(".\\private$\\" + name);
                    mq.Label = "private$\\" + name;
                    return true;
                }
                else
                {
                    return false;
                }
            }
            /// <summary>
            /// 删除一个消息队列
            /// </summary>
            /// <param name="name">消息队列的名称</param>
            /// <returns>是否创建成功</returns>
            public static bool DeleteNewMQ(string name)
            {
                if (!MessageQueue.Exists(".\\private$\\" + name))
                {
                    MessageQueue.Delete(".\\private$\\" + name);
                    return true;
                }
                else
                {
                    return false;
                }
            }
            /// <summary>
            /// 发送消息到指定消息队列
            /// </summary>
            /// <param name="mq_name">消息队列名称</param>
            /// <param name="msg_lable">消息头</param>
            /// <param name="msg_body">消息体</param>
            public static void SendMessage(string mq_name, string msg_lable, string msg_body)
            {
                MessageQueue mq = new MessageQueue(@".\private$\" + mq_name);
                Message message = new Message();
                message.Label = msg_lable;
                message.Body = msg_body;
                mq.Send(message);
            }
            /// <summary>
            /// 从指定消息队列获取第一条消息
            /// </summary>
            /// <param name="mq_name">消息队列名称</param>
            /// <returns>Message</returns>
            public static Message ReceiveMessage(string mq_name)
            {
                MessageQueue mq = new MessageQueue(@".\private$\" + mq_name);
                if (mq.GetAllMessages().Length > 0)
                {
                    Message message = mq.Receive();
                    if (message != null)
                    {
                        message.Formatter = new System.Messaging.XmlMessageFormatter(new Type[] { typeof(string) });
                    }
                    return message;
                }
                else
                {
                    return null;
                }
            }
        }
    }

在WPF中调用写好的方法：

using System;
using System.Timers;
using System.Windows;

namespace MQ
{
    public partial class MainWindow : Window
    {
        private static readonly string mq_name = "textMQ";
        private Timer timer;

        public MainWindow()
        {
            InitializeComponent();
            MQHelper.CreateNewMQ(mq_name);
            timer = new Timer();
            timer.Interval = 1000;
            timer.Elapsed += new System.Timers.ElapsedEventHandler(flash);
            timer.Start();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            string mq_content = inputText.Text;
            //发送一条消息到消息队列
            MQHelper.SendMessage(mq_name, "test", mq_content);
        }

        //循环获取消息队列中的消息，并展现到TextBox中
        private void flash(object sender, ElapsedEventArgs e)
        {
            var message = MQHelper.ReceiveMessage(mq_name);
            if (message != null)
            {
                Action hide = delegate()
                {
                    outputText.Text += message.Id + " " + message.Label + " " + message.Body + "\n";
                };
                this.Dispatcher.BeginInvoke(hide);
            }
        }
    }
}

运行结果：