Visitor访问模式_C#

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System;

namespace VisitorPatternExample1
{
    public class VisitorPatternExample1 : MonoBehaviour
    {
        void Start()
        {
            // Setup employee collection
            Employees e = new Employees();
            e.Attach(new Clerk());
            e.Attach(new Director());
            e.Attach(new President());

            // Employees are 'visited'
            e.Accept(new IncomeVisitor());
            e.Accept(new VacationVisitor());
            e.Accept(new Vacation2Visitor());

        }
    }

    /// <summary>
    /// 访问者
    /// </summary>
    interface IVisitor
    {
        void Visit(Element element);
    }

    /// <summary>
    ///查询收入
    /// </summary>
    class IncomeVisitor : IVisitor
    {
        public void Visit(Element element)
        {
            Employee employee = element as Employee;

            // 更改查询内容
            employee.Income *= 1.10;
            Debug.Log(employee.GetType().Name+" "+ employee.Name+"'的收入: "+employee.Income);
        }
    }

    /// <summary>
    /// 查询年龄
    /// </summary>
    class VacationVisitor : IVisitor
    {
        public void Visit(Element element)
        {
            Employee employee = element as Employee;


            employee.age += 3;
            Debug.Log(employee.GetType().Name + " " + employee.Name + "'的年龄:" + employee.age);
        }
    }
    /// <summary>
    /// 查询年龄2
    /// </summary>
    class Vacation2Visitor : IVisitor
    {
        public void Visit(Element element)
        {
            Employee employee = element as Employee;
            //内容的确发生变化了
            Debug.Log(employee.GetType().Name + " " + employee.Name + "'的年龄:" + employee.age);
        }
    }

    /// <summary>
    /// The 'Element' abstract class
    /// </summary>
    abstract class Element
    {
        public abstract void Accept(IVisitor visitor);
    }

    /// <summary>
    /// The 'ConcreteElement' class
    /// </summary>
    class Employee : Element
    {
        private string _name;
        private double _income;
        private int _age;

        // Constructor
        public Employee(string name, double income,
          int age)
        {
            this._name = name;
            this._income = income;
            this._age = age;
        }


        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }


        public double Income
        {
            get { return _income; }
            set { _income = value; }
        }


        public int age
        {
            get { return _age; }
            set { _age = value; }
        }

        public override void Accept(IVisitor visitor)
        {
            visitor.Visit(this);
        }
    }

    /// <summary>
    /// The 'ObjectStructure' class
    /// </summary>
    class Employees
    {
        private List<Employee> _employees = new List<Employee>();

        public void Attach(Employee employee)
        {
            _employees.Add(employee);
        }

        public void Detach(Employee employee)
        {
            _employees.Remove(employee);
        }

        public void Accept(IVisitor visitor)
        {
            foreach (Employee e in _employees)
            {
                e.Accept(visitor);
            }
        }
    }

    // Three employee types

    class Clerk : Employee
    {
        // Constructor
        public Clerk()
          : base("Hank", 25000.0, 14)
        {
        }
    }

    class Director : Employee
    {
        // Constructor
        public Director()
          : base("Elly", 35000.0, 16)
        {
        }
    }

    class President : Employee
    {
        // Constructor
        public President()
          : base("Dick", 45000.0, 21)
        {
        }
    }
}