C#事件机制复习

    class Person
    {

        public string name;
        public int age;
        public string sex;
        public float money;
        public Person()
        {
            this.name = "张三";
            this.age = 18;
            this.sex = "男";
            this.money = 1000;
        }
        public Person(string name, int age, string sex,float money)
        {
            this.name = name;
            this.age = age;
            this.sex = sex;
            this.money = money;
        }

    }
    class Custom : Person
    {
       public delegate void BuyEventHandler(object sender);
       public event BuyEventHandler BuyEvent; 

       public void Buy()
       {
           if(this.money==0)
               BuyEvent(this);
       }
    }
    class Seller:Person
    {
       
        public Seller(Custom c)
        {
            c.BuyEvent += new Custom.BuyEventHandler(this.Warning);
        }

        public void Warning(object sender)
        {
           
            Console.WriteLine("没钱了请充值！");
        }
    }
    

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

// 定义事件包含数据 
public class MyEventArgs : EventArgs
{
    private string StrText;
    public MyEventArgs(string StrText)
    {
        this.StrText = StrText;
    }
    public string GetStrText
    {
        get
        {
            return StrText;
        }
    }
}
// 发布事件的类 
class EventSource
{
    MyEventArgs EvArgs = new MyEventArgs("触发事件");
    // 定义委托 
    public delegate void EventHandler(object sender, MyEventArgs e);
    // 定义事件 
    public event EventHandler TextOut;
    // 激活事件的方法 
    public void TriggerEvent()
    {
        if (TextOut == null)
            TextOut(this, EvArgs);
    }
} 
// 订阅事件的类 
class TestApp
{
    public static void Main()
    {
        EventSource evsrc = new EventSource();
        // 订阅事件 
        evsrc.TextOut += new EventSource.EventHandler(CatchEvent);
        // 触发事件 
        evsrc.TriggerEvent();
        Console.WriteLine("------");
        // 取消订阅事件 
        evsrc.TextOut -= new EventSource.EventHandler(CatchEvent);
        // 触发事件 
        evsrc.TriggerEvent();
        Console.WriteLine("------");  // 事件订阅已取消，什么也不执行 
        TestApp theApp = new TestApp();
        evsrc.TextOut += new EventSource.EventHandler(theApp.InstanceCatch);
        evsrc.TriggerEvent();
        Console.WriteLine("------");
    }
    // 处理事件的静态方法 
    public static void CatchEvent(object from, MyEventArgs e)
    {
        Console.WriteLine("CatchEvent:{0}", e.GetStrText);
    }
    // 处理事件的方法 
    public void InstanceCatch(object from, MyEventArgs e)
    {
        Console.WriteLine("InstanceCatch：{0},e.GetStrText");
    }
}