设计模式学习笔记--迭代器模式

Posted 2020-07-17 bzyzhang

 1 using System;
 2 
 3 namespace Iterator
 4 {
 5     /// <summary> 
 6     /// 作者：bzyzhang
 7     /// 时间：2016/5/30 20:01:24 
 8     /// 博客地址：http://www.cnblogs.com/bzyzhang/
 9     /// Iterator说明：迭代器抽象类
10     /// </summary> 
11     public abstract class Iterator
12     {
13         public abstract object First();
14         public abstract object Next();
15         public abstract bool IsDone();
16         public abstract object CurrentItem();
17     }
18 }

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 1 using System;
 2 
 3 namespace Iterator
 4 {
 5     /// <summary> 
 6     /// 作者：bzyzhang
 7     /// 时间：2016/5/30 20:03:19 
 8     /// 博客地址：http://www.cnblogs.com/bzyzhang/
 9     /// Aggregate说明：聚集抽象类 
10     /// </summary> 
11     public abstract class Aggregate
12     {
13         public abstract Iterator CreateIterator();
14     }
15 }

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 1 using System;
 2 using System.Collections.Generic;
 3 
 4 namespace Iterator
 5 {
 6     /// <summary> 
 7     /// 作者：bzyzhang
 8     /// 时间：2016/5/30 20:06:13 
 9     /// 博客地址：http://www.cnblogs.com/bzyzhang/
10     /// ConcreteAggregate说明：具体聚集类，继承Aggregate
11     /// </summary> 
12     public class ConcreteAggregate:Aggregate
13     {
14         private List<object> items = new List<object>();
15 
16         public override Iterator CreateIterator()
17         {
18             return new ConcreteIterator(this);
19         }
20 
21         public int Count
22         {
23             get
24             {
25                 return items.Count;
26             }
27         }
28 
29         public object this[int index]
30         {
31             get
32             {
33                 return items[index];
34             }
35             set
36             {
37                 items.Insert(index,value);
38             }
39         }
40     }
41 }

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 1 using System;
 2 
 3 namespace Iterator
 4 {
 5     /// <summary> 
 6     /// 作者：bzyzhang
 7     /// 时间：2016/5/30 20:04:19 
 8     /// 博客地址：http://www.cnblogs.com/bzyzhang/
 9     /// ConcreteIterator说明：具体迭代器类，继承Iterator
10     /// </summary> 
11     public class ConcreteIterator:Iterator
12     {
13         private ConcreteAggregate aggregate;
14         private int current = 0;
15 
16         public ConcreteIterator(ConcreteAggregate aggregate)
17         {
18             this.aggregate = aggregate;
19         }
20 
21         public override object First()
22         {
23             return aggregate[0];
24         }
25 
26         public override object Next()
27         {
28             object ret = null;
29             ++current;
30             if(current <aggregate.Count)
31                 ret = aggregate[current];
32             return ret;
33         }
34 
35         public override bool IsDone()
36         {
37             return current >= aggregate.Count ? true : false;
38         }
39 
40         public override object CurrentItem()
41         {
42            return aggregate[current];
43         }
44     }
45 }

View Code

 1 using System;
 2 
 3 namespace Iterator
 4 {
 5     class Program
 6     {
 7         static void Main(string[] args)
 8         {
 9             ConcreteAggregate a = new ConcreteAggregate();
10 
11             a[0] = "大鸟";
12             a[1] = "小菜";
13             a[2] = "行李";
14             a[3] = "老外";
15             a[4] = "公交内部员工";
16             a[5] = "小偷";
17 
18             Iterator iterator = new ConcreteIterator(a);
19 
20             object item = iterator.First();
21 
22             while (!iterator.IsDone())
23             {
24                 Console.WriteLine("{0}请买车票！",iterator.CurrentItem());
25                 iterator.Next();
26             }
27         }
28     }
29 }

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