事件的例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace ConsoleApplication1
{
    public delegate void SalaryCompute(object sender, MyEventArgs e);        //声明一个代理类

    public class Employee
    {
        public event SalaryCompute OnSalaryCompute;         //定义事件，将其与代理绑定

        public virtual void FireEvent(MyEventArgs e)       //触发事件的方法
        {
            if (OnSalaryCompute != null)
            {
                OnSalaryCompute(this, e);      //触发事件
            }
        }
    }

    public class MyEventArgs : EventArgs         //定义事件参数类
    {
        public readonly double _salary;
        public MyEventArgs(double salary)
        {
            this._salary = salary;
        }
    }

    public class HumanResource
    {
        public void SalaryHandler(object sender, MyEventArgs e)          //事件处理函数，其签名应与代理签名相同
        {
            Console.WriteLine("Salary is {0}", e._salary);     //只是打印一行字而已
        }

        public static void Main()
        {
            Employee ep = new Employee();
            HumanResource hr = new HumanResource();
            MyEventArgs e = new MyEventArgs(123.40);
            ep.OnSalaryCompute += new SalaryCompute(hr.SalaryHandler);       //将打印一行文字的方法注册到事件中
            for (; ; )
            {
                Thread.Sleep(1000);      //让程序“睡”一秒
                ep.FireEvent(e);        //触发事件
            }
            //Console.Read();
        }
    }
}