C#学习：事件

        类或对象可以通过事件向其他类或对象通知发生的相关事情。 发送（或引发）事件的类称为“发行者”，接收（或处理）事件的类称为“订阅者”。

• 一个简单事件实例

      //发行者
      public class Student
      {
          private string name;
  
          //定义一个带参委托
          public delegate void DelegateRegisterFinish(string name);
          //定义一个事件
          public event DelegateRegisterFinish EventRegisterFinish;
  
          public Student(string name)
          {
              this.name = name;
          }
  
          //在一定条件下，发行者发布事件
          public void Register()
          {
              Console.WriteLine("学生{0}进行注册", name);
              if (EventRegisterFinish != null)
                  EventRegisterFinish(name);
          }
      }

      //订阅者
      class RegisterStudent
      {
          static void Main(string[] args)
          {
              Console.WriteLine("输入学生姓名：");
              string studentName = Console.ReadLine();
              Console.WriteLine("--------------------------------------");
  
              Student student = new Student(studentName);
  
              //为静态方法student_EventRegisterFinishOne订阅事件
              //C#1.0语法
              student.EventRegisterFinish += new
                  Student.DelegateRegisterFinish(student_EventRegisterFinishOne);
              //C#2.0语法
              //student.EventRegisterFinish += student_EventRegisterFinishOne;
  
              //为RegisterStudent实例对象的student_EventRegisterFinishTwo方法订阅事件
              //本处其实利用多路广播委托为多个方法订阅事件
              RegisterStudent rs = new RegisterStudent();
              student.EventRegisterFinish += rs
                  .student_EventRegisterFinishTwo;
  
              //发行者发布事件后订阅者做相应的操作
              student.Register();
  
              Console.WriteLine("--------------------------------------");
              //取消订阅
              student.EventRegisterFinish -= rs
                  .student_EventRegisterFinishTwo;
              student.Register();
  
              Console.Read();
          }
          private static void student_EventRegisterFinishOne(string name)
          {
              Console.WriteLine("{0}注册成功", name);
          }
          private void student_EventRegisterFinishTwo(string name)
          {
              Console.WriteLine("{0}请及时领取住宿用品", name);
          }
      }

  结果：