关于外观模式实现的快速问题

Question

关于我个人的外观模式实现，我有一个简短的问题，只是为了确保我理解正确:我有一个名为Car的类，它被认为是Engine和Lights的外观。另外，我还有一个Driver类，它可以为不同类型的汽车调用方法。我的代码是否满足正确实现外观模式的要求？

#include <iostream>
#include <memory>

class Engine
{
public:
    void turnOn()
    {
        std::cout << "Engine turned on. \n";
    }
};

class Lights
{
public:
    void turnOn()
    {
        std::cout << "Lights turned on. \n";
    }
};

class Car // Facade for Engine and Lights
{
private:
    std::shared_ptr<Engine> m_engine;
    std::shared_ptr<Lights> m_lights;
public:
    Car(std::shared_ptr<Engine> engine, std::shared_ptr<Lights> lights) : m_engine{ engine }, m_lights{ lights } {}
    void turnCarOn()
    {
        std::cout << "Turning car on... \n";
        m_engine->turnOn();
        m_lights->turnOn();
    }
};

class Driver // Facade for Car
{
private:
    std::shared_ptr<Car> m_car;
public:
    Driver(std::shared_ptr<Car> car) : m_car{ car } {}
    void turnCarOn()
    {
        std::cout << "Driver presses some buttons... \n";
        m_car->turnCarOn();
    }
};

int main()
{
    std::shared_ptr<Engine> engine = std::make_shared<Engine>();
    std::shared_ptr<Lights> lights = std::make_shared<Lights>();
    std::shared_ptr<Car> car = std::make_shared<Car>(engine, lights);
    std::shared_ptr<Driver> driver = std::make_shared<Driver>(car);
    driver->turnCarOn();
}

Answer 1

是的，您的实现满足要求。

能够为不同种类的汽车提供Facade，需要Facade不仅盲目地将调用转发到它隐藏的组件，还需要配置特定Car的组件集。

您可以在共享指针m_engine和m_lights的帮助下实现这一点

有关权威参考的更精确的论证，您可以查看this answer to another SO question (它是用于java的)。