public sealed class MachineParameters
    {
        // Singleton
        public static readonly MachineParameters instance = new MachineParameters();
        public static MachineParameters GetInstance()
        {
            return instance;
        }

        // 为了实现类似单例的全局调用效果，因此想到
        public Machine M1 = new Machine(1);
        public Machine M2 = new Machine(2);
        public Machine M3 = new Machine(3);
        public Machine M4 = new Machine(4);

        // 为了便于轮询，将所有 Machine 类实例放入数组
        public Machine[] M = new Machine[4];

        private MachineParameters()
        {
            M[1] = M1;
            M[2] = M2;
            M[3] = M3;
            M[4] = M4;
        }
    }

    public sealed class TimingController
    {
        // Singleton
        private static readonly TimingController instance = new TimingController();
        public static TimingController GetInstance()
        {
            return instance;
        }

        MachineParameters Machines = MachineParameters.GetInstance();

        // 方便的全局式调用如下
        Machines.M[i].Speed = 100;
    }

    public class Machine //实例类
    {
**(1)        TimingController Timing = TimingController.GetInstance();
        UpdateData Update = UpdateData.GetInstance();
        //省略其余定义
        //类中用到了 TimingController 和 UpdateData ，因此声明如上
        public Machine(int id)
        {
**(2)            Timing.WarmedUp += new TimingEventHandler(Update.UpdateMachine);
        }
    }


    public partial class MainWindow : Form
    {
        // Singleton
        //public static readonly MainWindow instance = new MainWindow();
        //public static MainWindow GetInstance()
        //{
        //    return instance;
        //}

        // 主窗体类，程序从这里开始
***(3)        TimingController Timing = TimingController.GetInstance();
    }

static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
**(4)            Application.Run(new MainWindow());
        }
    }