//策略模式
#include <iostream>
using namespace std;
/*
策略模式
和简单工厂模式类似，策略是简单工厂模式中的一个对象
包含在一个客户对象中。
*/
/*
使用场景：策略是客户对象的一部分，使用这种方法可以
实现更换策略的无关低耦合
*/
class Strategy {
public:
virtual void AlgorithmInterface() =
0;
};
class StrategyClass1 :
public Strategy {
public:
void AlgorithmInterface() {
cout<<
"Class 1"<<
endl;
}
};
class StrategyClass2 :
public Strategy {
public:
void AlgorithmInterface() {
cout<<
"Class 2"<<
endl;
}
};
class Context {
private:
Strategy*
m_pStrategy;
public:
Context(char ch)
{
m_pStrategy =
NULL;
switch(ch)
{
case '1':
m_pStrategy =
new StrategyClass1();
break;
case '2':
m_pStrategy =
new StrategyClass2();
break;
}
}
~
Context()
{
delete m_pStrategy;
}
void ContextInterface()
{
m_pStrategy->
AlgorithmInterface();
}
};
int main()
{
Context* p1 =
new Context(
'1');
p1->
ContextInterface();
delete p1;
Context* p2 =
new Context(
'2');
p2->
ContextInterface();
delete p2;
return 0;
}
//简单工厂模式
#include <iostream>
using namespace std;
/*
简单工厂模式
根据用户输入生成继承于同一个接口的对象
返回值为基类对象指针，用户可以通过这个指针操作接口方法
*/
/*
使用场景：面临着功能性的需求变化，并提供功能的接口一致
使用简单工厂模式可以简单的提供扩展，只需要对于工厂的生
成方法进行改写就可以得到不同对象。
*/
class Operation {
public:
double m_dNumberA;
double m_dNumberB;
public:
virtual double GetResult() =
0;
};
class OperationAdd :
public Operation
{
public:
double GetResult()
{
return (m_dNumberA +
m_dNumberB);
}
};
class OperationSub :
public Operation
{
public:
double GetResult()
{
return (m_dNumberA -
m_dNumberB);
}
};
class OperationMul :
public Operation
{
public:
double GetResult()
{
return (m_dNumberA *
m_dNumberB);
}
};
class OperationDiv :
public Operation
{
public:
double GetResult()
{
if (m_dNumberB ==
0)
return -
1;
return (m_dNumberA /
m_dNumberB);
}
};
//工厂类
class OperationFactory {
public:
static Operation* CreateOperate(
char operate)
{
Operation* pOperation =
NULL;
switch (operate)
{
case '+':
pOperation =
new OperationAdd();
break;
case '-':
pOperation =
new OperationSub();
break;
case '*':
pOperation =
new OperationMul();
break;
case '/':
pOperation =
new OperationDiv();
break;
}
return pOperation;
}
};
int main()
{
Operation* pOperation = OperationFactory::CreateOperate(
'+');
pOperation->m_dNumberA =
3;
pOperation->m_dNumberB =
4;
cout<<pOperation->GetResult()<<
endl;
delete pOperation;
return 0;
}
转载于:https://www.cnblogs.com/yanjiu/archive/2012/08/05/2623590.html
相关资源：数据结构—成绩单生成器
