原型模式(16)

原型模式

用原型指定创建对象的种类，并且通过拷贝这些原型创建新的对象

其关键点在于clone函数，调用clone函数来创建更多相同类型的对象

#include<iostream>
#include<list>
using namespace std;
//父类  Resume:简历
class Resume  
{  
protected: char *name;//有指针类型，防止浅拷贝
public: Resume() {} virtual ~Resume() {} virtual Resume* Clone() { return NULL; }  //关键函数
	virtual void Set(char *n) {} virtual void Show() {}  
}; class ResumeA : public Resume  
{  
public: ResumeA(){}
	ResumeA(char *str);  //构造函数  
	ResumeA(const ResumeA &r); //拷贝构造函数  
	~ResumeA(); //析构函数  
	ResumeA* Clone(); //克隆，关键所在  
	void Show(); //显示内容  
};  
ResumeA::ResumeA(char *str) { if(str == NULL) 
	{ name = new char[1]; name[0] = '\0'; } else//切记要深拷贝，不要浅拷贝
	{ name = new char[strlen(str)+1]; strcpy(name, str); } //浅拷贝代码如下
	//name = str;
}  
ResumeA::~ResumeA()
{ 
	delete [] name;
}  
ResumeA::ResumeA(const ResumeA &r)
{ name = new char[strlen(r.name)+1]; strcpy(name, r.name);  
}  
ResumeA* ResumeA::Clone() 
{ return new ResumeA(*this); 
	//直接调用类的拷贝构造函数
	//其实也可以在本函数内自己实现拷贝构造函数的内容
	//代码如下
	/*
	ResumeA * m_sum = new ResumeA();
	if(name == NULL) 
	{ m_sum->name = new char[1]; m_sum->name[0] = '\0'; } else//切记要深拷贝，不要浅拷贝
	{ m_sum->name = new char[strlen(name)+1]; strcpy(m_sum->name, name); } return m_sum;
	*/
}  
void ResumeA::Show()
{ cout<<"ResumeA name : "<<name<<endl; } int main()  
{ Resume *r1 = new ResumeA("A"); Resume *r2 = new ResumeA("B"); Resume *r3 = r1->Clone(); Resume *r4 = r2->Clone(); r1->Show(); r2->Show(); //删除r1,r2  
	delete r1; delete r2; r1 = r2 = NULL; cout<<"-----------------------"<<endl;
	//深拷贝所以对r3,r4无影响  
	r3->Show();
	r4->Show(); delete r3; delete r4; r3 = r4 = NULL;  
}


  

 

  
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文章来源: blog.csdn.net，作者：IM-STONE，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/doubleintfloat/article/details/110455397