//构造函数
AirConditioner::AirConditioner(string strAirName, int nTemperature)
{
	m_strAirName = strAirName;
	m_nTemperature = nTemperature;

	m_pNormalTemperatureState = new NormalTemperatureState();
	m_pRefrigerateState = new RefrigerateState();
	m_pHeatState = new HeatState();

	m_pCurState = m_pNormalTemperatureState;
}



//虚构函数
AirConditioner::~AirConditioner()
{
	delete m_pNormalTemperatureState;
	m_pNormalTemperatureState = NULL;

	delete m_pRefrigerateState;
	m_pRefrigerateState = NULL;

	delete m_pHeatState;
	m_pHeatState = NULL;
}
	



//调节温度
void AirConditioner::SetTemperature(int nTemperature)
{
	m_nTemperature = nTemperature;
}



//获取温度
int AirConditioner::GetTemperature()
{
	return m_nTemperature;
}



//设置空调状态
void AirConditioner::SetAirConditionerState(AirConditionerState * pAirConditionerState)
{
	m_pCurState = pAirConditionerState;
}





//获取常温状态
AirConditionerState * AirConditioner::GetNormalTemperatureState()
{
	return m_pNormalTemperatureState;
}




//获取制冷状态
AirConditionerState * AirConditioner::GetRefrigerateState()
{
	return m_pRefrigerateState;
}




//获取制热状态
AirConditionerState * AirConditioner::GetHeatState()
{
	return m_pHeatState;
}





//保持常温
void AirConditioner::KeepNormalTemperature()
{
	m_pCurState->KeepNormalTemperature(this);
	
}




//制冷
void AirConditioner::refrigerate()
{
	m_pCurState->refrigerate(this);
}




//制热
void AirConditioner::Heat()
{
	m_pCurState->Heat(this);
}

#include 
  
   
#include "AirConditioner.h"

using namespace std;

int main()
{

	AirConditioner * pAirConditioner = new AirConditioner("海尔空调", 25);

	/****************常温状态*************************/
	pAirConditioner->KeepNormalTemperature();

	cout << endl;
	
	/****************制冷状态*************************/
	pAirConditioner->SetTemperature(33);
	pAirConditioner->refrigerate();

	cout << endl;

	/****************制热状态*************************/
	pAirConditioner->SetTemperature(15);
	pAirConditioner->Heat();

	/****************销毁操作*************************/
	delete pAirConditioner;
	pAirConditioner = NULL;

	return 0;
}
  

将具体行为封装在常温状态、制冷状态、制热状态中。空调类(也就是环境类)维持一个当前状态的引用，当客户端调用环境类的方法时，将该调用操作委托给具体状态类。具体状态类实现该状态下的行为，以及控制切换到其他状态。客户端无需直接操作具体的状态类，而是由环境类代为处理，降低了客户端与具体状态类的耦合性。如果需要添加具体的状态类也很容易，只需要继承于抽象状态类并对环境类稍加修改就可以了。另外，也避免了大量if...else臃肿语句，把这些条件判断都封装成一个个状态类。