using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace learningLab
{
    class growUPEventArgs:EventArgs
    {
        public string Message {get;set;}
        public growUPEventArgs(string message)
        {
            this.Message=message;
        }
    }
 
    abstract class person
    {
        private string _name;
        private int _age;
 
        public string Name
        {
            get
            {
                return _name;
            }
        }
 
        public int Age
        {
            get
            {
                return _age;
            }
        }
 
        public person(string name,int age)
        {
            this._age = age;
            this._name = name;
 
        }
 
 
        //这里并没有使用委托而是使用了泛型的EventHandler，可以节约一行代码
        public event EventHandler<growUPEventArgs> GrowUPEvent;
 
        protected virtual void OnGrowUp(growUPEventArgs e)
        {
            //handler是一个临时变量，防止被一个竞争占用
            EventHandler<growUPEventArgs> handler = GrowUPEvent;
            //若handler不为空，则发行一个事件,this就是发行者person
            if (handler != null)
            {
                handler(this, e);
            }
        }
        // 定义一个方法来触发事件
       public abstract void growUp();
    }
 
    class student : person
    {
        public student(string name, int age) : base(name, age) { }
 
       protected override void OnGrowUp(growUPEventArgs e)
       {
           base.OnGrowUp(e);
       }
 
       public override void growUp()
       {
           this.OnGrowUp(new growUPEventArgs("Yeah,I'm getting older!"));
           //throw new NotImplementedException();
       }
 
    }
 
    class teacher : person
    {
        public teacher(string name, int age) : base(name, age) { }
 
        protected override void OnGrowUp(growUPEventArgs e)
        {
            base.OnGrowUp(e);
        }
 
        public override void growUp()
        {
            this.OnGrowUp(new growUPEventArgs("Oh,NO!I'm getting older!"));
            //throw new NotImplementedException();
        }      
    }
 
    class InAclassRoom
    {
        private  List<person> _PersonList;
 
        public InAclassRoom()
        { 
            _PersonList=new List<person>();
        }
 
        public void addPeople(person p)
        {
            _PersonList.Add(p);
            p.GrowUPEvent += HandlerYourGrowUp;
 
        }
 
        private void HandlerYourGrowUp(object o,growUPEventArgs e)
        {
            Console.WriteLine(e.Message);
        }
 
        public List<person> getThePersonList()
        {
            return _PersonList;
        } 
    }
 
    class Program
    {
        public static void Main()
        {
            teacher t = new teacher("MicroTeach", 40);
            student s = new student("Shaomingbo", 23);
            InAclassRoom classRoom = new InAclassRoom();
            classRoom.addPeople(t);
            classRoom.addPeople(s);
            //订阅了事件，但未触发。按回车后，方可触发;
            //此处说明了，事件发行者决定事件<何时发生>
            Console.WriteLine("You decide:<Enter>");
            Console.ReadLine();
            List<person> plist = classRoom.getThePersonList();
            foreach (person p in plist)
            {
                Console.WriteLine("Hi, My Name is " + p.Name + ",and i'm " + p.Age + " years old.");
                Console.WriteLine("Actually ,i'm a " + p.GetType());
                Console.WriteLine("When I feel getting older,i'd say :");
                p.growUp();
                Console.WriteLine();
            }
            Console.ReadLine();
        }
    }  
}
/*Output:
You decide:<Enter>
 
Hi, My Name is MicroTeach,and i'm 40 years old.
Actually ,i'm a learningLab.teacher
When I feel getting older,i'd say :
Oh,NO!I'm getting older!
 
Hi, My Name is Shaomingbo,and i'm 23 years old.
Actually ,i'm a learningLab.student
When I feel getting older,i'd say :
Yeah,I'm getting older!
*/