发布订阅者模式之C#委托实现

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 委托与发布订阅者模式
{

    /**
     * 机器Machine为被订阅者，维修工Repairer为订阅者
     * 工人（订阅者）注册机器的不同事件，并注册回调函数以当相应事件发生时进行处理
     * 不同的工人可以只关注他们各自感兴趣的事件
     */
    // 机器类
    public class Machine
    {
        // 机器是否正常工作状态
        public bool IsWorkWell { get; set; }

        // 机器故障事件委托
        public delegate void MachineBroken(string brokenMsg);
        public event MachineBroken MachineBrokenEvent;

        // 机器正常工作事件委托
        public delegate void MachineWorkWell(string msg);
        public event MachineWorkWell MachineWorkWellEvent;

        // 机器运作
        public void Run()
        {
            IsWorkWell = false; // 设置机器出故障

            if (MachineBrokenEvent != null) // 有订阅者注册机器故障事件
            {
                if (!IsWorkWell)
                    MachineBrokenEvent("机器出故障了，速度过来看下啊，亲~");
            }

            IsWorkWell = true; // 设置机器恢复正常

            if (MachineWorkWellEvent != null) // 有订阅者注册机器运行正常事件
            {
                if (IsWorkWell)
                    MachineWorkWellEvent("机器正常运作，不用担心，亲~");
            }
        }

        //public void OnMachineBrokenEvent(string brokenmsg)
        //{
        //    MachineBroken handler = machineBrokenEvent;
        //    if (handler != null) handler(brokenmsg);
        //}

        //public void OnMachineWorkWellEvent(string msg)
        //{
        //    MachineWorkWell handler = machineWorkWellEvent;
        //    if (handler != null) handler(msg);
        //}
    }

    public interface IWorker
    {
        string Name { get; set; }
        void DoJob(string msg);
    }

    // BusyWorker注册机器故障事件
    public class BusyWorker: IWorker
    {
        public string Name { get; set; }

        public void DoJob(string msg)
        {
            Console.WriteLine(string.Format("{0}： 收到信息 < {1} > ！马上过来处理，稍等啊~", Name, msg));
        }
    }

    // IdleWorker注册机器正常工作事件
    public class IdleWorker: IWorker
    {
        public string Name { get; set; }

        public void DoJob(string msg)
        {
         Console.WriteLine(string.Format("{0}: 收到信息 < {1} > ！非常好，这样我就可以多睡会了~", Name, msg));   
        }
    }

    public class SubscriberPatternViaDelegate
    {
        static void Main(string[] args)
        {
            Machine machine = new Machine();

            IWorker busyWorker = new BusyWorker();
            busyWorker.Name = "Busy Worker";

            IWorker idleWorker = new IdleWorker();
            idleWorker.Name = "Idle Worker";

            machine.MachineBrokenEvent += new Machine.MachineBroken(busyWorker.DoJob);
            machine.MachineWorkWellEvent += new Machine.MachineWorkWell(idleWorker.DoJob);

            ///////////////////////////////////////////////////////////////////////////////////////////
            // 下面开始验证是否可以为一个事件添加多个订阅者
            IWorker busyWorker2 = new BusyWorker();
            busyWorker2.Name = "Busy Worker 2";
            machine.MachineBrokenEvent += new Machine.MachineBroken(busyWorker2.DoJob);
            // 试验结果是可以的
            // 同样可以使用静态委托，静态委托的好处之一是节省了内存空间
            ///////////////////////////////////////////////////////////////////////////////////////////

            machine.Run();  // 机器开始运作

            Console.ReadLine();
        }
    }
}