C# 使用Microsoft消息队列(MSMQ)

写在前面

Microsoft Message Queuing (MSMQ) 是在多个不同的应用之间实现相互通信的一种异步传输模式，相互通信的应用可以分布于同一台机器上，也可以分布于相连的网络空间中的任一位置。

使用消息队列可以实现异步通讯，无需关心接收端是否在线，只需发出后就可以继续处理后续的任务，通讯双方也可以是不同的物理平台，该机制还可以用来实现故障恢复。

在使用前，需要先确认该功能是否安装和启用，如未安装可以参考以下操作步骤：

进入控制面板\所有控制面板项\程序和功能，点击启用或关闭Windows功能，勾选Microsoft消息队列，确认并安装。

消息队列分为以下几种，每种队列的路径表示形式如下：

公用队列 MachineName\QueueName

专用队列 MachineName\Private$\QueueName

日记队列 MachineName\QueueName\Journal$

计算机日记队列 MachineName\Journal$

计算机死信队列 MachineName\Deadletter$

计算机事务性死信队列 MachineName\XactDeadletter$

代码实现

需要引用 System.Messaging 类库

using System.Messaging;

发送端

    public partial class Form1 : Form{MessageQueue queue;string path = ".\\Private$\\testQueue";public Form1(){InitializeComponent();CreateMessageQueue();}private void button1_Click(object sender, EventArgs e){SendMessage(this.textBox1.Text);}private void CreateMessageQueue(){if(MessageQueue.Exists(path)){queue = new MessageQueue(path);}else{queue = MessageQueue.Create(path);}}private void SendMessage(string str){var message = new System.Messaging.Message();message.Formatter = new XmlMessageFormatter(new Type[]{ typeof(string)});message.Body = str;queue.Send(message);MessageBox.Show("消息发送成功");}private void SendMessage(Image image){var message = new System.Messaging.Message();message.Formatter = new BinaryMessageFormatter();message.Body = image;queue.Send(message);MessageBox.Show("图像发送成功");}private void button2_Click(object sender, EventArgs e){OpenFileDialog open = new OpenFileDialog();open.Filter = "图像文件|*.jpg;*.bmp;*.png";open.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);if(open.ShowDialog() == DialogResult.OK){Image image = Bitmap.FromFile(open.FileName);SendMessage(image);}}private void button3_Click(object sender, EventArgs e){MessageBox.Show(queue.GetAllMessages().Length.ToString());}private void button4_Click(object sender, EventArgs e){queue.Purge();}}

接收端

    public partial class Form1 : Form{MessageQueue queue;string path = ".\\Private$\\testQueue";public Form1(){InitializeComponent();CreateMessageQueue();}private void button1_Click(object sender, EventArgs e){RecvStringMessage();}private void button2_Click(object sender, EventArgs e){RecvImageMessage();}private void CreateMessageQueue(){if (MessageQueue.Exists(path)){queue = new MessageQueue(path);}else{queue = MessageQueue.Create(path);}}public void RecvStringMessage(){if (queue.GetAllMessages().Length == 0){MessageBox.Show("消息队列为空");return;}var message = queue.Receive();message.Formatter = new XmlMessageFormatter(new Type[] {typeof(string) });MessageBox.Show(message.Body.ToString());}public void RecvImageMessage(){if (queue.GetAllMessages().Length == 0){MessageBox.Show("消息队列为空");return;}var message = queue.Receive();message.Formatter = new BinaryMessageFormatter();Image image = (Image)message.Body;Form form = new Form();form.Width = 1024;form.Height = 768;PictureBox pbox = new PictureBox();pbox.Width = 1024;pbox.Height = 768;pbox.SizeMode = PictureBoxSizeMode.Zoom;pbox.Image = image;form.Controls.Add(pbox);form.ShowDialog();}}