PHP状态模式

####状态设计模式* 状态模式的作用是允许对象在状态改变时改变其行为* 对象中频繁的状态非常依赖于条件语句,就自身来说条件语句并没有什么问题,不过,如果选项太多,以至于程序出现混乱,或者增加或改变选项需要太多的是时间。```offState = new OffState($this);        $this->onState = new Onstate($this);        $this->brighterState = new BrighterState($this);        $this->brightestState = new BrightestState($this);        $this->currentState = $this->offState;    }    public function  turnOnLight(){        $this->currentState->turnLightOn();    }    public function turnOffLight(){        $this->currentState->turnLightOff();    }    public function turnBrighter(){        $this->currentState->turnBrighter();    }    public function turnBrightest(){        $this->currentState->turnBrightest();    }    public function setState(IState $state){        $this->currentState = $state;    }    public function getOnState(){        return $this->onState;    }    public function getOffState(){        return $this->offState;    }    public function getBrighterState(){        return $this->brighterState;    }    public function getBrightestState(){        return $this->brightestState;    }}interface IState{    public function turnLightOn();    public function turnLightOff();    public function turnBrighter();    public function turnBrightest();}class Onstate implements IState{    private $context;    public function __construct(Context $contextNew)    {        $this->context = $contextNew;    }    public function turnLightOff()    {        echo "Lights off"."";        $this->context->setState($this->context->getOffState());    }    public function turnLightOn()    {        echo "Light is already on there is no action"."";    }    public function turnBrighter()    {        echo "turn 明亮"."";    }    public function turnBrightest()    {        echo "turn 最亮"."";    }}class OffState implements IState{    private $context;    public function __construct(Context $contextNew)    {     $this->context = $contextNew;    }    public function turnLightOn()    {       echo "Lights On Now i can see"."";        $this->context->setState($this->context->getOnState());    }    public function turnLightOff()    {       echo "Light is already off"."";    }    public function turnBrightest()    {        echo "turn 最亮"."";    }    public function turnBrighter()    {        echo "turn 较亮"."";    }}class BrighterState implements IState{    private $context;    public function __construct(Context $contextNow)    {        $this->context = $contextNow;    }    public function turnBrighter()    {        echo "变暗了";    }    public function turnBrightest()    {     $this->context->setState($this->context->getBrighterState());    }    public function turnLightOff()    {        echo "关灯了";    }    public function turnLightOn()    {        echo "灯是亮的";    }}class BrightestState implements IState{    private $context;    public function __construct(Context $contextNow)    {        $this->context = $contextNow;    }    public function turnLightOff()    {        $this->context->setState($this->context->getOffState());    }    public function turnBrightest()    {        echo "this is brightest"."";    }    public function turnBrighter()    {       echo "this is a little 暗淡"."";    }    public function turnLightOn()    {        echo "there is no use"."";    }}class Client{    private $context;    public function __construct()    {        $this->context = new Context();        $this->context->turnOnLight();        $this->context->turnOnLight();        $this->context->turnOffLight();        $this->context->turnOffLight();        $this->context->turnOnLight();        $this->context->turnBrighter();        $this->context->turnBrightest();        $this->context->turnOffLight();    }}$data = new Client();```