一道委托的题目

Question

学生类
班长类继承学生类
班长负责巡查。
学生抄作业一次,扣5份，二次10分，以此类推。
学生存在一个list里面，抄作业的学生是随机的。
问用委托实现。

Answer 1

在学生类里定义一个委托,再申明一个事件,
事件在main里注册,
去研究一下自定义事件

Answer 2

class Xuesheng
{
int chufaCount=0;
public  delegate boolean  OnChaoxiing()
public OnChaoxiing Chaoxiingｐｒｉｖａｔｅ　void chufa()
{
chufaCount++；
}public void chaoxi()
{
if (!=null &&　Chaoxiing())
{
chufa()；
}}
}
xuesheng.Chaoxiing+=banzhangInstance.XXXXXclass Banzhang : Xuesheng
{ public boolean XXXXX()
{
//自定义处理 }}

Answer 3

刚才写了一个代码 不过貌似出问题了..
能看看不？using System;
using System.Collections.Generic;
using System.Text;namespace Delegate
{
     // 学生    public class Student 
    {
       public string Name = "";
        public int Tmies = 0;
        public Student(string name)
        {
            Name = name;
        }
        //声明委托
        public delegate void CatchedEventHandler(Object sender, CatchEventArgs e);                public event CatchedEventHandler Boiled;       
        public class CatchEventArgs : EventArgs
        {
            public readonly string name;
            public CatchEventArgs(string name)
            {
                this.name = name;
            }
        }       
        protected virtual void OnBoiled(CatchEventArgs e)
        {
            if (Boiled != null)
            {
                Boiled(this, e);  
            }
        }
   
 
    
        public void CatchStudent(Student student)
        {
            CatchEventArgs e = new CatchEventArgs(student.Name);
                    OnBoiled(e); 
            
        }
    }    public class Master : Student
    {
        public Master(string name) : base(name)
        {
        }        public void MakeAlert(Object sender, CatchEventArgs e)
        {
            Student student = (Student)sender;            student.Tmies++;
            Console.WriteLine("Alarm：{0}抓住了{1}童鞋,今天第{2}次: ",this.Name, student.Name, student.Tmies);
            Console.WriteLine("Alarm: 已经被扣了{0} 分了：", student.Tmies * 5);
            Console.WriteLine();
        }
    }
    class Program
    {
        static void Main()
        {            Master alarmMaster = new Master("我是五条杠");
            var studentSelect = new List<Student>();
            var studentAll=new List<Student>();
            for (int i = 0; i < 10; i++)
            {
                var student=new Student("学生"+i);
                studentAll.Add(student);
            }
            for (int i = 0; i < 5; i++)
            {
                Random random = new Random(i);
                studentSelect.Add(studentAll[random.Next(9)]);
            }            foreach (var student in studentSelect)
            {
                student.CatchStudent(student);
                student.Boiled += alarmMaster.MakeAlert;   //注册方法
              
            }
            Console.ReadLine();
        }
    }
}

Answer 4

public class Student
    {
        public Student(string strName)
        {
            Name = strName;
            Score = 100;
            ChaoZuoYeCount = 0;
            IsChaoZuoYe = false;
        }        public string Name { get; set; }
        public int Score { get; set; }
        public int ChaoZuoYeCount { get; set; }
        public bool IsChaoZuoYe { get; set; }        public override string ToString()
        {
            string strSpilt = "\t";
            StringBuilder sb = new StringBuilder();
            sb.Append("Name: " + Name + strSpilt);
            sb.Append("Score: " + Score + strSpilt);
            sb.Append("ChaoZuoYeCount: " + ChaoZuoYeCount + strSpilt);
            return sb.ToString();
        }
    }    public delegate void WatchStudent(Student student);    public class StudentLeader : Student
    {
        public StudentLeader(string strName)
            : base(strName)
        {        }        public WatchStudent WatchHandler { get; set; }
        public void Watch(Student student)
        {
            if (WatchHandler != null)
            {
                WatchHandler(student);
            }
        }
    }    public class DelegateDemo
    {
        public void DoTest()
        {
            List<Student> students = new List<Student>()
            {
                new Student("Student A"),
                new Student("Student B"),
                new Student("Student C"),
                new Student("Student D"),
                new Student("Student E"),
            };
            StudentLeader leader = new StudentLeader("Leader");
            leader.WatchHandler = DoWatch;            int testCount = 10;
            Random rand = new Random();
            for (int i = 0; i < testCount; i++)
            {
                foreach (Student student in students)
                {
                    if (rand.Next(1, 10) % 2 == 0)
                    {
                        student.IsChaoZuoYe = true;
                    }
                    leader.Watch(student);
                }
            }
            Console.ReadKey();
        }        public void DoWatch(Student student)
        {
            if (student == null)
            {
                return;
            }
            if (student.IsChaoZuoYe)
            {
                student.Score += 5;
                student.ChaoZuoYeCount++;
            }            Console.WriteLine(student.ToString());
        }
    }

Answer 5

    以后修改了扣分规则只要修改DelegateDemo.DoWatch里面的规则就可以,
 对student类修改进行封闭.