C#中的委托和事件

namespace Delegate {

        // 热水器        public class Heater {

               private int temperature;

               public string type = "RealFire 001";

              // 添加型号作为演示

               public string area = "China Xian";

                     // 添加产地作为演示

               //声明委托

               public delegate void BoiledEventHandler(Object sender, BoliedEventArgs e);

               public event BoiledEventHandler Boiled; 

      //声明事件

              // 定义BoliedEventArgs类，传递给Observer所感兴趣的信息

               public class BoliedEventArgs : EventArgs {

                      public readonly int temperature;

                      public BoliedEventArgs(int temperature) {

                             this.temperature = temperature;

                      }

               }

              // 可以供继承自 Heater 的类重写，以便继承类拒绝其他对象对它的监视

               protected virtual void OnBolied(BoliedEventArgs e) {

                      if (Boiled != null) {

       // 如果有对象注册

                             Boiled(this, e);

       // 调用所有注册对象的方法

                      }

               }

                             // 烧水。

               public void BoilWater() {

                      for (int i = 0; i <= 100; i++) {

                             temperature = i;

                             if (temperature > 95) { 

                                   //建立BoliedEventArgs 对象。

                                    BoliedEventArgs e = new BoliedEventArgs(temperature);

                                    OnBolied(e);       // 调用 OnBolied方法

                             }

                      }

               }

        }

       // 警报器        public class Alarm {

               public void MakeAlert(Object sender, Heater.BoliedEventArgs e) {

                      Heater heater = (Heater)sender; 

             //这里是不是很熟悉呢？

                      //访问 sender 中的公共字段

                      Console.WriteLine("Alarm：{0} - {1}: ", heater.area, heater.type);

                      Console.WriteLine("Alarm: 嘀嘀嘀，水已经 {0} 度了：", e.temperature);

                      Console.WriteLine(); 

              }

       }

       // 显示器        public class Display {

               public static void ShowMsg(Object sender, Heater.BoliedEventArgs e) {

       //静态方法

                      Heater heater = (Heater)sender; 

                     Console.WriteLine("Display：{0} - {1}: ", heater.area, heater.type);

                      Console.WriteLine("Display：水快烧开了，当前温度：{0}度。", e.temperature);

                      Console.WriteLine(); 

              }

        }

       class Program {

               static void Main() {

                      Heater heater = new Heater(); 

                     Alarm alarm = new Alarm();

                     heater.Boiled += alarm.MakeAlert;

       //注册方法

                      heater.Boiled += (new Alarm()).MakeAlert;

              //给匿名对象注册方法

                      heater.Boiled += new Heater.BoiledEventHandler(alarm.MakeAlert);

       //也可以这么注册

                      heater.Boiled += Display.ShowMsg; 

             //注册静态方法

                     heater.BoilWater();

       //烧水，会自动调用注册过对象的方法

               } 

       }

 }