factory.cpp

设计模式 几个常见的设计模式源代码 Delegation Factory等

#include <iostream>
using namespace std;

static const double PI = 3.14;

class Shape
{
public:
	virtual double Area() = 0;
};

class Rectangle : public Shape
{
public:
    Rectangle( int width, int height );

public:
	double Area();

private:
	int _width;
	int _height;
};

Rectangle::Rectangle( int width, int height ) 
{
	_width = width;
	_height = height;
}

double Rectangle::Area()
{
	return _width*_height;
}

class Circle : public Shape
{
public:
	Circle( int radius );

public:
	double Area();

private:
	int _radius;
};

class Creator
{
	virtual Shape* CreateShape() = 0;
};

class RectCreator
{
	Shape* CreateShape()
	{
		Rectangle* rect = new Rectangle( 10, 20 );
		return rect;
	}
};

class CircleCreator
{
	Shape* CreateShape()
	{
		Circle* rect = new Circle( 10 );
		return rect;
	}
}; 

void Compute( Creator* pCreator )
{
	Shape* pShape = pCreator->CreateShape();
	pShape->Area();
	delete pShape;
	pShape = NULL;
}

int main()
{
	CircleShape cs;
	RectShape   rs;
	
	Compute( &cs );
	Compute( &rs );
	
    return 0;	
}