软件设计——备忘录模式之多次撤销C++

改进课堂上的“用户信息操作撤销”实例，使得系统可以实现多次撤销（可以使用HashMap、ArrayList等集合数据结构实现）。

类图：

代码：

#include<iostream>
#include<string>
#include<vector>
using namespace std;
/*
struct State {
	string account;
	string password;
	string telNo;
};
class Memento {
private:
	State* state;
public:
	Memento(State* pstate) :state(pstate) {}
	State* getState() {
		return state;
	}
};
*/
//备忘录
class Memento {
private:
	string account;
	string password;
	string telNo;
public:
	Memento(string account, string password, string telNo) {
		this->account = account;
		this->password = password;
		this->telNo = telNo;
	}

	string getAccount() {
		return account;
	}
	void setAccount(string account) {
		this->account = account;
	}
	string getPassword() {
		return password;
	}
	void setPassword(string password) {
		this->password = password;
	}

	string getTelNo() {
		return telNo;
	}
	void setTelNo(string telNo) {
		this->telNo = telNo;
	}
};
//发起者
class UserInfoDTO {
private:
	string account;
	string password;
	string telNo;
public:
	string getAccount() {
		return account;
	}
	void setAccount(string account) {
		this->account = account;
	}
	string getPassword() {
		return password;
	}
	void setPassword(string password) {
		this->password = password;
	}

	string getTelNo() {
		return telNo;
	}
	void setTelNo(string telNo) {
		this->telNo = telNo;
	}

	Memento saveMemento() {
		Memento memento(account, password, telNo);
		return memento;
	}

	void restoreMenmento(Memento memento) {
		this->account = memento.getAccount();
		this->password = memento.getPassword();
		this->telNo = memento.getTelNo();
	}

	void show() {
		cout << "Account" + this->account << endl;
		cout << "Password" + this->password << endl;
		cout << "TelNo" + this->telNo << endl;
	}
};
//管理者
class Caretaker {
private:
	vector<Memento>mementos;
public:
	Memento getMemento(int i) {
		return mementos.at(i);
	}
	void setMemento(Memento memento) {
		mementos.push_back(memento);
	}
};

int main() {
	int index = -1;
	UserInfoDTO user;
	Caretaker taker;

	user.setAccount("zhangsan");
	user.setPassword("123456");
	user.setTelNo("13000000000");
	cout << "状态一：" << endl;
	taker.setMemento(user.saveMemento());
	index++;
	user.show();
	cout << "----------------------------------" << endl;

	user.setPassword("111111");
	user.setTelNo("13100001111");
	cout << "状态二：" << endl;
	taker.setMemento(user.saveMemento());
	index++;
	user.show();
	cout << "----------------------------------" << endl;

	user.setPassword("222222");
	user.setTelNo("13100001111");
	cout << "状态三：" << endl;
	user.show();
	cout << "----------------------------------" << endl;

	cout << "回到状态二:" << endl;
	index--;
	user.restoreMenmento(taker.getMemento(1));
	user.show();
	cout << "----------------------------------" << endl;

	cout << "回到状态一:" << endl;
	index --;
	user.restoreMenmento(taker.getMemento(0));
	user.show();
	cout << "----------------------------------" << endl;

}

运行结果：