设计模式_迭代器模式

迭代器模式

介绍

设计模式	定义	案例
迭代器模式	行为型：关注对象与行为的分离 提供了一种统一的方式来访问多个不同的集合	两个集合：使用了不同的数据存储方式 学生 和 警察 查询显示出集合的内容 ，使用相同的代码

问题堆积在哪里	解决办法
不同的存储方式 统一集合查询代码	1 统一出一个存储方式 2 设计一个查询基类来统一查询代码 3 每个集合提供   1 统一存储方式，   2 一个查询实现（接口迭代器的实现）

类图

代码

interface BaseIterator<T>

/// <summary>
/// 迭代器基类
/// </summary>
public interface BaseIterator<T>
{// 当前T Current();// 下一个bool MoveNext();// 重新开始void Reset();
}

IteratorPolice 

using System.Collections.Generic;public class IteratorPolice : BaseIterator<People>
{// 列表List<People> listPeople = null;// 下标int currentIndex = -1;  IteratorPolice() { }public IteratorPolice(List<People> list){listPeople = list;}public People Current(){if (null == listPeople)return null;if (listPeople.Count < currentIndex)return null;return listPeople[currentIndex];}public bool MoveNext(){if (null == listPeople)return false;if (listPeople.Count > ++currentIndex)return true;return false;}public void Reset(){currentIndex = -1;}
}

IteratorStudent 

using System.Collections.Generic;public class IteratorStudent : BaseIterator<People>
{// 列表List<People> listPeople = null;// 下标int currentIndex = -1;IteratorStudent() { }public IteratorStudent(List<People> list){listPeople = list;}public People Current(){if (null == listPeople)return null;if (listPeople.Count < currentIndex)return null;return listPeople[currentIndex];}public bool MoveNext(){if (null == listPeople)return false;if (listPeople.Count > ++currentIndex)return true;return false;}public void Reset(){currentIndex = -1;}}

People

public class People
{public string name;public int age;public bool married;
}

StudentList

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class StudentList
{private List<People> list = new List<People>();private People[] studentList = new People[3];public StudentList(){People p1 = new People(){name = "WH",age = 15,married = false};studentList[0] = p1;People p2 = new People(){name = "QT",age = 16,married = false};studentList[1] = p2;People p3 = new People(){name = "YY",age = 15,married = false};studentList[2] = p3;for (int i = 0; i < studentList.Length; i++){list.Add(studentList[i]);}}public BaseIterator<People> GetIterator(){return new IteratorStudent(list);}
}

PoliceList

using System.Collections.Generic;public class PoliceList
{private List<People> list = new List<People>();public PoliceList(){People p1 = new People(){name = "WangQiang",age = 23,married = false};list.Add(p1);People p2 = new People(){name = "ZhangQiang",age = 30,married = true};list.Add(p2);People p3 = new People(){name = "LingQiang",age = 31,married = true};list.Add(p3);}public BaseIterator<People> GetIterator(){return new IteratorPolice(list); }
}

测试代码

using UnityEngine;public class TestDDQ : MonoBehaviour
{void Start(){{PoliceList pl = new PoliceList();BaseIterator<People> iterator = pl.GetIterator();while (iterator.MoveNext()){People p1 = iterator.Current();Debug.Log("姓名：" + p1.name + "   年龄：" + p1.age + "   是否结婚：" + p1.married + " ");}}Debug.Log("------------------------------------------------------------------");{StudentList pl = new StudentList();BaseIterator<People> iterator = pl.GetIterator();while (iterator.MoveNext()){People p1 = iterator.Current();Debug.Log("姓名：" + p1.name + "   年龄：" + p1.age + "   是否结婚：" + p1.married + " ");}}}
}

结果

总结

迭代器模式统一集合查询代码，以这个为目标进现优化总结出的一个经验。

还是为了更深刻的理解设计原理和优化手段。