C# 中发送和接收MSMQ的一个示例

Ok, 直接上代码:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
    public class Form1 : Form
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.label1 = new System.Windows.Forms.Label();
            this.button3 = new System.Windows.Forms.Button();
            this.label2 = new System.Windows.Forms.Label();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(198, 52);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(143, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "Send Message";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(12, 52);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(157, 23);
            this.button2.TabIndex = 1;
            this.button2.Text = "Received Message";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(151, 94);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(31, 13);
            this.label1.TabIndex = 2;
            this.label1.Text = "none";
            // 
            // button3
            // 
            this.button3.Location = new System.Drawing.Point(366, 52);
            this.button3.Name = "button3";
            this.button3.Size = new System.Drawing.Size(157, 23);
            this.button3.TabIndex = 3;
            this.button3.Text = "Stop Receiveing";
            this.button3.UseVisualStyleBackColor = true;
            // 
            // label2
            // 
            this.label2.AutoSize = true;
            this.label2.Location = new System.Drawing.Point(12, 94);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(133, 13);
            this.label2.TabIndex = 4;
            this.label2.Text = "Received a new message:";
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(565, 146);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Button button3;
        private System.Windows.Forms.Label label2;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            System.Messaging.MessageQueue mq;

            // 如果不存在google这个队列, 那么创建这个队列
            if (System.Messaging.MessageQueue.Exists(".\\google"))
            {
                mq = new System.Messaging.MessageQueue(".\\google");
            }
            else
                mq = System.Messaging.MessageQueue.Create(".\\google");
            mq.Purge();// 将队列清空
            // 向队列中发送一条消息, 1个随机的数字, 并使用XML序列化进行传输
            mq.Send(new System.Messaging.Message(new Random().NextDouble(), new System.Messaging.XmlMessageFormatter()));

        }



        private void Fn()
        {
            var mq = new System.Messaging.MessageQueue(".\\google")
            {
                Formatter = new System.Messaging.XmlMessageFormatter(new[] { typeof(double) })
            };
            while (true)
            {
                var message = mq.Receive();
                if (null != message)
                    Invoke(Convert.ToString(message.Body));
                Thread.Sleep(100);
            }

        }

        private delegate void Do(string str);


        private void Set(string str)
        {
            label1.Text = str;
        }

        // 默认情况下, Window form是不允许被非创建它的线程进行访问的, 所以要通过delegate进行安全调用
        // 可以通过设置 Control.CheckForIllegalCrossThreadCalls = false; 来取消跨线程调用的限制
        private void Invoke(string str)
        {
            var foo = new Do(Set);
            // 可以看到: 是label1 这个控件去调用foo, 是种主动行为. 这样就不会引用跨线程调用异常
            label1.Invoke(foo, str);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            // 创建一个新的线程去接收队列中的消息
            var ts = new ThreadStart(Fn);
            var th = new Thread(ts);
            MessageBox.Show(@"Start Receiving");
            th.Start();
        }
    }
}

有几个点可以说一下:

1. 首先得有队列, 在没有队列的情况下, new System.Messaging.MessageQueue(“.\\google”) 是会有异常的, 所以得先判断和创建队列通道:

            System.Messaging.MessageQueue mq;

            // 如果不存在google这个队列, 那么创建这个队列
            if (System.Messaging.MessageQueue.Exists(".\\google"))
            {
                mq = new System.Messaging.MessageQueue(".\\google");
            }
            else
                mq = System.Messaging.MessageQueue.Create(".\\google");

2. window form 默认情况下不可被非创建它的线程进行访问. 这个问题, 简单点的方法是允许它被其它线程访问:

Control.CheckForIllegalCrossThreadCalls = false;

但是这样其实会有一个跨线程访问的风险存在, 是非安全的. 建议的方法是通过delegate的方法, 让控件自己去invoke需要调用的方法, 是一种由被动修改变为主动出击的方式.

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