文章目录
一、前言
状态模式理解最基本上的我觉得应该也是够用了,实际用的话,也应该用的是Boost.MSM
状态机。
相关代码可以在这里,如有帮助给个star!AidenYuanDev/design_patterns_in_modern_Cpp_20
二、实现
一、UML类图
二、实现
c
#include <iostream>
#include <memory>
using namespace std;
class Light_Switch;
class On_State;
class Off_State;
class State {
public:
virtual void on(Light_Switch* ls) = 0;![请添加图片描述](https://i-blog.csdnimg.cn/direct/9c069a22ebae485d8dbd3f084c658e5d.png)
virtual void off(Light_Switch* ls) = 0;
};
class On_State : public State {
public:
On_State() { cout << "灯打开了" << endl; }
void on(Light_Switch* ls) override {}
void off(Light_Switch* ls) override;
};
class Off_State : public State {
public:
Off_State() { cout << "灯灭了" << endl; }
void on(Light_Switch* ls) override;
void off(Light_Switch* ls) override {}
};
class Light_Switch {
private:
shared_ptr<State> state_;
public:
Light_Switch() : state_(make_shared<Off_State>()) {}
void set_state(shared_ptr<State> state) { state_ = std::move(state); }
void on() { state_->on(this); }
void off() { state_->off(this); }
};
void On_State::off(Light_Switch* ls) {
cout << "按下关灯键" << endl;
ls->set_state(make_shared<Off_State>());
}
void Off_State::on(Light_Switch* ls) {
cout << "按下开灯键" << endl;
ls->set_state(make_shared<On_State>());
}
int main() {
auto ls = make_shared<Light_Switch>();
ls->on();
ls->off();
ls->on();
return 0;
}