c++之建造者模式

建造者模式

定义：将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示

属于创建型模式

代码：

#include <iostream>
#include <vector>
#include <iostream>

using namespace std;

//电脑产品
class Computer
{
public:
	void addPart(string p)
	{
		m_vecParts.push_back(p);
	}
	void showDetails()
	{
		cout << "电脑建造过程：" << endl;
		for (string x : m_vecParts)
		{
			cout << x.c_str() << endl;
		}
	}
private:
	vector<string> m_vecParts;
};

class Builder
{
public:
	virtual ~Builder(){}
	virtual void buildScreen() = 0;
	virtual void buildKeyboard() = 0;
	virtual Computer* getComputer() = 0;
};

class ConcreteBuilderA :public Builder
{
public:
	ConcreteBuilderA() :m_computer(nullptr)
	{
		m_computer = new Computer;
	}
	~ConcreteBuilderA()
	{
		if (m_computer)
		{
			delete m_computer;
			m_computer = nullptr;
		}
	}
	void buildScreen()
	{
		m_computer->addPart("电脑屏幕A");
	}
	void buildKeyboard()
	{
		m_computer->addPart("内设键盘A");
	}

	Computer* getComputer()
	{
		return m_computer;
	}

private:
	Computer *m_computer;
};

class ConcreteBuilderB :public Builder
{
public:
	ConcreteBuilderB() :m_computer(nullptr)
	{
		m_computer = new Computer;
	}
	~ConcreteBuilderB()
	{
		if (m_computer)
		{
			delete m_computer;
			m_computer = nullptr;
		}
	}
	void buildScreen()
	{
		m_computer->addPart("电脑屏幕B");
	}
	void buildKeyboard()
	{
		m_computer->addPart("内设键盘B");
	}

	Computer* getComputer()
	{
		return m_computer;
	}

private:
	Computer *m_computer;
};

class Director
{
public:
	void build(Builder *build)
	{
		build->buildScreen();
		build->buildKeyboard();
	}
};

//客户端
int main()
{
	Director *director = new Director;

	Builder *buildA = new ConcreteBuilderA;
	Builder *buildB = new ConcreteBuilderB;
	director->build(buildA);
	Computer *computerA = buildA->getComputer();
	computerA->showDetails();

	director->build(buildB);
	Computer *computerB = buildB->getComputer();
	computerB->showDetails();

	if (director)
	{
		delete director;
		director = nullptr;
	}
	if (buildA)
	{
		delete buildA;
		buildA = nullptr;
	}
	if (buildB)
	{
		delete buildB;
		buildB = nullptr;
	}

	return 0;
}

效果：