C#学习小记9包装类以封装预定义类集群

using System;

using System.Collections;

public class Student

{

public string a="89";

}

public class EnrollmentCollection

{

private ArrayList students;

public EnrollmentCollection()

{

students=new ArrayList();

}

public void Enroll(Student s)

{

students.Add(s);

}

}

public class Course

{

private EnrollmentCollection enrolledStudents;

public Course()

{

enrolledStudents=new EnrollmentCollection();

}

public void Enroll(Student s)

{

enrolledStudents.Enroll(s);

}

}

public class Do

{ static void Main()

{

Course a=new Course();

Student b=new Student();

Student c=new Student();

Student d=new Student();

a.Enroll(b);a.Enroll(c);a.Enroll(d);

}

}