add Iterator Pattern

16.InterpreterPattern/2.Code/InterpreterPattern.h

@@ -1,5 +1,5 @@
-#ifndef __COMMAND_PATTERN_H__
-#define __COMMAND_PATTERN_H__
+#ifndef __INTERPRETOR_PATTERN_H__
+#define __INTERPRETOR_PATTERN_H__
 
 #include <vector>
 using namespace std;
@@ -126,4 +126,4 @@ private:
 };
 
 
-#endif //__COMMAND_PATTERN_H__
+#endif //__INTERPRETOR_PATTERN_H__

17.IteratorPattern/2.Code/Aggregate.cpp

@@ -0,0 +1,21 @@
+#include "Iterator.h"
+
+Television::Television(){}
+
+Television::Television(vector<string> iChannelList){
+	this->channelList = iChannelList;
+}
+
+Iterator* Television::createIterator(){
+	RemoteControl *it = new RemoteControl();
+	it->setTV(this);
+	return (Iterator*)it;
+}
+
+int Television::getTotalChannelNum(){
+	return channelList.size();
+}
+
+void Television::play(int i){
+	printf("现在播放：%s……\n", channelList[i].c_str());
+}

17.IteratorPattern/2.Code/Aggregate.h

@@ -0,0 +1,34 @@
+#ifndef __AGGREGATE_H__
+#define __AGGREGATE_H__
+
+#include <vector>
+using namespace std;
+
+// 前向声明，因为两个类互相引用
+class Iterator;
+class RemoteControl;
+
+// 抽象聚合类 Aggregate
+class Aggregate
+{
+public:
+	Aggregate(){}
+	virtual Iterator* createIterator() = 0;
+};
+
+// 具体聚合类 Television
+class Television :public Aggregate
+{
+public:
+	Television();
+	Television(vector<string> iChannelList);
+	// 实现创建迭代器
+	Iterator* createIterator();
+	// 获取总的频道数目
+	int getTotalChannelNum();
+	void play(int i);
+private:
+	vector<string> channelList;
+};
+
+#endif //__AGGREGATE_H__

17.IteratorPattern/2.Code/Iterator.h

@@ -0,0 +1,69 @@
+#ifndef _ITERATOR_H_
+#define _ITERATOR_H_
+
+#pragma once
+#include "Aggregate.h"
+
+#include <vector>
+using namespace std;
+
+// 抽象迭代器
+class Iterator
+{
+public:
+	Iterator(){}
+	// 声明抽象遍历方法
+	virtual void first() = 0;
+	virtual void last() = 0;
+	virtual void next() = 0;
+	virtual void previous() = 0;
+	virtual bool hasNext() = 0;
+	virtual bool hasPrevious() = 0;
+	virtual void currentChannel() = 0;
+private:
+
+};
+
+// 遥控器：具体迭代器
+class RemoteControl :public Iterator
+{
+public:
+	RemoteControl(){}
+	void setTV(Television *iTv){
+		this->tv = iTv;
+		cursor = -1;
+		totalNum = tv->getTotalChannelNum();
+	}
+	// 实现各个遍历方法
+	void first(){
+		cursor = 0;
+	}
+	void last(){
+		cursor = totalNum - 1;
+	}
+	void next(){
+		cursor++;
+	}
+	void previous(){
+		cursor--;
+	}
+	bool hasNext(){
+		return !(cursor == totalNum);
+	}
+	bool hasPrevious(){
+		return !(cursor == -1);
+	}
+	void currentChannel(){
+		tv->play(cursor);
+	}
+private:
+	// 游标
+	int cursor;
+	// 总的频道数目
+	int totalNum;
+	// 电视
+	Television* tv;
+};
+
+
+#endif

17.IteratorPattern/2.Code/main.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+#include "Iterator.h"
+
+int main()
+{
+	vector<string> channelList = { "新闻频道", "财经频道", "体育频道", "电影频道", "音乐频道", "农业频道", "四川卫视", "成都卫视" };
+	// 创建电视
+	Television *tv = new Television(channelList);
+	// 创建遥控器
+	Iterator *remoteControl = tv->createIterator();
+
+	// 顺序遍历
+	printf("顺序遍历:\n");
+	remoteControl->first();
+	// 遍历电视所有频道
+	while (remoteControl->hasNext()){
+		remoteControl->currentChannel();
+		remoteControl->next();
+	}
+
+	printf("\n\n");
+
+	// 逆序遍历
+	printf("逆序遍历:\n");
+	remoteControl->last();
+	// 遍历电视所有频道
+	while (remoteControl->hasPrevious()){
+		remoteControl->currentChannel();
+		remoteControl->previous();
+	}
+
+	printf("\n\n");
+	system("pause");
+	return 0;
+}

README.md

@@ -77,4 +77,8 @@ Jungle设计模式系列
 
 19.设计模式（十九）——解释器模式
 
-博客地址：https://blog.csdn.net/sinat_21107433/article/details/102864850
+博客地址：https://blog.csdn.net/sinat_21107433/article/details/102864850
+
+20.设计模式（二十）——迭代器模式
+
+博客地址：https://blog.csdn.net/sinat_21107433/article/details/102879383