Technologieaustausch

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I. Einleitung

Ich denke, das grundlegendste Verständnis des Zustandsmusters sollte ausreichen. Wenn es tatsächlich verwendet wird, sollte es auch so seinBoost.MSMZustandsmaschine.

Den entsprechenden Code finden Sie hier. Wenn es hilft, geben Sie ihm einen Stern!AidenYuanDev/Designmuster im modernen Cpp20

2. Erkenntnis

1. UML-Klassendiagramm

2. Erkenntnis

#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;
}
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