设计模式：decade模式

目的：为系统中的一组联动接口提供一个高层次的接口，从而降低系统的复杂性

优点：使用窗口模式可以使得接口变少

继承关系图：

例子：

class Subsystem1
{
public:
    void Operation()
	{
		cout << "Subsystem1::Operation" << endl;
	}
};

class Subsystem2
{
public:
    void Operation()
	{
		cout << "Subsystem2::Operation" << endl;
	}
};

class Facade
{
private:
    Subsystem1* _subsys1;
    Subsystem2* _subsys2;

public:
    Facade()
	{
		this->_subsys1 = new Subsystem1();
		this->_subsys2 = new Subsystem2();
	}

    ~Facade()
	{
		delete this->_subsys1;
		delete this->_subsys2;
	}

    void OperationWrapper()
	{
		this->_subsys1->Operation();
		this->_subsys2->Operation();
	}
};

int main()
{
	Facade* pFacade = new Facade();
	pFacade->OperationWrapper();

	return 0;
}