namespace Delegates{    partial class Form1 : Form    {        public Form1()        {            InitializeComponent();            clock = new Clock(digital);        }        private void start_Click(object sender, System.EventArgs e)        {            this.clock.Start();        }        private void stop_Click(object sender, System.EventArgs e)        {            this.clock.Stop();        }        private Clock clock;    }}

Clock.cs类的内容

namespace Delegates{    using System.Windows.Forms;    class Clock    {        public Clock(TextBox displayBox)        {            this.display = displayBox;        }        public void Start()        {            pulsed.Add(this.RefreshTime);        }        public void Stop()        {            pulsed.Remove(this.RefreshTime);        }        private delegate void InvokeCallback(string msg);        private void RefreshTime(int hh, int mm, int ss)        {            if (!this.display.InvokeRequired)            {                this.display.Text = string.Format("{0:D2}:{1:D2}:{2:D2}", hh, mm, ss);            }            else            {                InvokeCallback msgCallback = new InvokeCallback(DisplayText);                display.Invoke(msgCallback, new object[] { string.Format("{0:D2}:{1:D2}:{2:D2}", hh, mm, ss) });            }        }        private void DisplayText(string text)        {            this.display.Text = text;        }        private Ticker pulsed = new Ticker();        private TextBox display;    }}

 

namespace Delegates{    using System.Collections;    using System.Timers;    using System.Windows.Forms;    class Ticker    {        public delegate void Tick(int hh, int mm, int ss);        public Ticker()        {            this.ticking.Elapsed += new ElapsedEventHandler(this.OnTimedEvent);            this.ticking.Interval = 1000; // 1 second            this.ticking.Enabled = true;        }        public void Add(Tick newMethod)        {            this.tickers += newMethod;        }        public void Remove(Tick oldMethod)        {            this.tickers -= oldMethod;        }        private void Notify(int hours, int minutes, int seconds)        {            if (this.tickers != null)            {                this.tickers(hours, minutes, seconds);            }        }        private void OnTimedEvent(object source, ElapsedEventArgs args)        {            int hh = args.SignalTime.Hour;            int mm = args.SignalTime.Minute;            int ss = args.SignalTime.Second;            Notify(hh, mm, ss);        }        private Tick tickers;        private System.Timers.Timer ticking = new System.Timers.Timer();    }}

 

Ticker.cs类的内容