委托与事件

public abstract class AbstractThread

    {

        Thread thread = null;



        public abstract void run();



        public void start()

        {

            if (thread == null)

                thread = new Thread(new ThreadStart(run));

            thread.Start();

        }

    }public delegate void TimeEventHandler(object obj, TimeEventArgs args); 

    public class EventThread : AbstractThread
    {
        public EventThread()
        {
            IsAlive = true;
        }

        public event TimeEventHandler TimeChanged;

        public bool IsAlive { get; set; }

        public override void run()
        {
            DateTime initi = DateTime.Now;
            int h1 = initi.Hour;
            int m1 = initi.Minute;
            int s1 = initi.Second;
            while (IsAlive)
            {
                DateTime now = DateTime.Now;
                int h2 = now.Hour;
                int m2 = now.Minute;
                int s2 = now.Second;
                if (s2 != s1)
                {
                    h1 = h2;
                    m1 = m2;
                    s1 = s2;

                    //首先建立一个TimeEventArgs对象来保存相关参数，这里是时分秒。
                    TimeEventArgs args = new TimeEventArgs(h2, m2, s2);
                    TimeChanged(this, args);
                }
                Thread.Sleep(1000);
            }


        }
    }

    public class TimeEventArgs : EventArgs
    {
        private int hour;
        private int minute;
        private int second;
        public TimeEventArgs(int hour, int minute, int second)
        {
            this.hour = hour;
            this.minute = minute;
            this.second = second;
        }
        public int Hour
        {
            get
            {
                return hour;
            }
        }
        public int Minute
        {
            get
            {
                return minute;
            }
        }
        public int Second
        {
            get
            {
                return second;
            }
        }
    }