add Visitor Pattern

24.VisitorPattern/2.Code/Demo.h

@@ -0,0 +1,59 @@
+#ifndef __DEMO_H__
+#define __DEMO_H__
+
+// 抽象访问者 Visitor
+class Visitor
+{
+public:
+	virtual void visit(ConcreteElementA*) = 0;
+	virtual void visit(ConcreteElementB*) = 0;
+};
+
+// 具体访问者 ConcreteVisitor
+class ConcreteVisitor :public Visitor
+{
+public:
+	// 实现一种针对特定元素的访问操作
+	void visit(ConcreteElementA*){
+		// 元素A的访问操作代码
+	}
+	void visit(ConcreteElementB*){
+		// 元素B的访问操作代码
+	}
+};
+
+// 抽象元素
+class Element
+{
+public:
+	// 声明抽象方法，以一个抽象访问者的指针作为函数参数
+	virtual void accept(Visitor*) = 0;
+};
+
+// 具体元素
+class ConcreteElement :public Element
+{
+public:
+	void accept(Visitor* visitor){
+		visitor->visit(this);
+	}
+};
+
+// 对象结构
+class ObjectStructure
+{
+public:
+	//  提供接口接受访问者访问
+	void accept(Visitor* visitor){
+		// 遍历访问对象结构中的元素
+		for (){
+			elementList[i]->accept(visitor);
+		}
+	}
+	void addElement(){}
+	void removeElement(){}
+private:
+	lsit<Element*>elementList;
+};
+
+#endif

24.VisitorPattern/2.Code/Element.cpp

@@ -0,0 +1,34 @@
+#include "Element.h"
+
+/*****        Apple        *******/
+Apple::Apple(){
+	setPrice(0);
+	setNum(0);
+	setName("");
+}
+Apple::Apple(string name, int price){
+	setPrice(price);
+	setNum(0);
+	setName(name);
+}
+
+void Apple::accept(Visitor* visitor){
+	visitor->visit(this);
+}
+
+/*****        Book        *******/
+Book::Book(){
+	setPrice(0);
+	setNum(0);
+	setName("");
+}
+
+Book::Book(string iName, int iPrice){
+	setPrice(iPrice);
+	setNum(0);
+	setName(iName);
+}
+
+void Book::accept(Visitor* visitor){
+	visitor->visit(this);
+}

24.VisitorPattern/2.Code/Element.h

@@ -0,0 +1,56 @@
+#ifndef __ELEMENT_H__
+#define __ELEMENT_H__
+
+#include "Visitor.h"
+#include <iostream>
+using namespace std;
+
+// 抽象元素
+class Element
+{
+public:
+	Element(){};
+	virtual void accept(Visitor*) = 0;
+	void setPrice(int iPrice){
+		this->price = iPrice;
+	}
+	int getPrice(){
+		return this->price;
+	}
+	void setNum(int iNum){
+		this->num = iNum;
+	}
+	int getNum(){
+		return num;
+	}
+	void setName(string iName){
+		this->name = iName;
+	}
+	string getName(){
+		return this->name;
+	}
+private:
+	int price;
+	int num;
+	string name;
+};
+
+// 具体元素：Apple
+class Apple :public Element
+{
+public:
+	Apple();
+	Apple(string name, int price);
+	void accept(Visitor*);
+};
+
+// 具体元素：Book
+class Book :public Element
+{
+public:
+	Book();
+	Book(string name, int price);
+	void accept(Visitor*);
+};
+
+#endif

24.VisitorPattern/2.Code/ShoppingCart.h

@@ -0,0 +1,25 @@
+#ifndef __SHOPPINGCART_H__
+#define __SHOPPINGCART_H__
+
+#include "Element.h"
+#include "Visitor.h"
+#include <vector>
+
+class ShoppingCart
+{
+public:
+	ShoppingCart(){}
+	void addElement(Element* element){
+		printf("  商品名：%s, \t数量：%d, \t加入购物车成功！\n", element->getName().c_str(), element->getNum());
+		elementList.push_back(element);
+	}
+	void accept(Visitor* visitor){
+		for (int i = 0; i < elementList.size(); i++){
+			elementList[i]->accept(visitor);
+		}
+	}
+private:
+	vector<Element*>elementList;
+};
+
+#endif 

24.VisitorPattern/2.Code/Visitor.h

@@ -0,0 +1,45 @@
+#ifndef __VISITOR_H__
+#define __VISITOR_H__
+
+#include <iostream>
+using namespace std;
+
+// 前向声明
+class Element;
+class Apple;
+class Book;
+
+// 抽象访问者
+class Visitor
+{
+public:
+	Visitor(){};
+	// 声明一组访问方法
+	virtual void visit(Apple*) = 0;
+	virtual void visit(Book*) = 0;
+};
+
+// 具体访问者：顾客
+class Customer :public Visitor
+{
+public:
+	Customer();
+	Customer(string iName);
+	void setNum(Apple*, int);
+	void setNum(Book*, int);
+	void visit(Apple* apple);
+	void visit(Book* book);
+private:
+	string name;
+};
+
+// 具体访问者：收银员
+class Cashier :public Visitor
+{
+public:
+	Cashier();
+	void visit(Apple* apple);
+	void visit(Book* book);
+};
+
+#endif

24.VisitorPattern/2.Code/main.cpp

@@ -0,0 +1,36 @@
+#include "Element.h"
+#include "Visitor.h"
+#include "ShoppingCart.h"
+#include <Windows.h>
+
+int main()
+{
+	Apple *apple1 = new Apple("븐말却틥벎", 7);
+	Apple *apple2 = new Apple("빻큇틥벎", 5);
+	Book *book1 = new Book("븐짜촘", 129);
+	Book *book2 = new Book("老써諒", 49);
+
+	Cashier* cashier = new Cashier();
+	Customer* jungle = new Customer("Jungle");
+	jungle->setNum(apple1, 2);
+	jungle->setNum(apple2, 4);
+	jungle->setNum(book1, 1);
+	jungle->setNum(book2, 3);
+
+	ShoppingCart* shoppingCart = new ShoppingCart();
+	shoppingCart->addElement(apple1);
+	shoppingCart->addElement(apple2);
+	shoppingCart->addElement(book1);
+	shoppingCart->addElement(book2);
+
+	printf("\n\n");
+	shoppingCart->accept(jungle);
+
+	printf("\n\n");
+	shoppingCart->accept(cashier);
+
+
+	printf("\n\n");
+	system("pause");
+	return 0;
+}

24.VisitorPattern/2.Code/visitor.cpp

@@ -0,0 +1,50 @@
+#include "Visitor.h"
+#include "Element.h"
+
+/*****        Customer        *******/
+Customer::Customer(){
+	this->name = "";
+}
+
+Customer::Customer(string iName){
+	this->name = iName;
+}
+
+void Customer::setNum(Apple* apple, int iNum){
+	apple->setNum(iNum);
+}
+void Customer::setNum(Book* book, int iNum){
+	book->setNum(iNum);
+}
+
+void Customer::visit(Apple* apple){
+	int price = apple->getPrice();
+	printf("  %s \t单价: \t%d 元/kg\n", apple->getName().c_str(), apple->getPrice());
+}
+
+void Customer::visit(Book* book){
+	int price = book->getPrice();
+	string name = book->getName();
+	printf("  《%s》\t单价: \t%d 元/本\n", book->getName().c_str(), book->getPrice());
+}
+
+/*****        Cashier        *******/
+Cashier::Cashier(){
+
+}
+
+void Cashier::visit(Apple* apple){
+	string name = apple->getName();
+	int price = apple->getPrice();
+	int num = apple->getNum();
+	int total = price*num;
+	printf("  %s 总价： %d 元\n", name.c_str(), total);
+}
+
+void Cashier::visit(Book* book){
+	int price = book->getPrice();
+	string name = book->getName();
+	int num = book->getNum();
+	int total = price*num;
+	printf("  《%s》 总价： %d 元\n", name.c_str(), total);
+}