设计模式之状态模式(PHP实现)

/** * 在状态模式（State Pattern）中，类的行为是基于它的状态改变的。这种类型的设计模式属于行为型模式。 * 在状态模式中，我们创建表示各种状态的对象和一个行为随着状态对象改变而改变的 context 对象。 * 对象的行为依赖于它的状态（属性），并且可以根据它的状态改变而改变它的相关行为。 */

<?phpnamespace State;interface State{ ???public function doAction(Context $context);}

<?phpnamespace State;class Context{ ???private $state; ???public function __construct() ???{ ???????$this->state = null; ???} ???public function setState(State $state) ???{ ???????$this->state = $state; ???} ???public function getState() ???{ ???????return $this->state; ???}}

<?phpnamespace State;class Context{ ???private $state; ???public function __construct() ???{ ???????$this->state = null; ???} ???public function setState(State $state) ???{ ???????$this->state = $state; ???} ???public function getState() ???{ ???????return $this->state; ???}}

<?phpnamespace State;class StopState implements State{ ???public function doAction(Context $context) ???{ ???????echo "Player is in stop state"; ???????$context->setState($this); ???} ???public function handle() ???{ ???????return ‘stop state‘; ???}}

<?phpspl_autoload_register(function ($className){ ???$className = str_replace(‘\\‘,‘/‘,$className); ???include $className.".class.php";});use State\Context;use State\StartState;use State\StopState;$context = new ?Context();$startState = new StartState();$startState->doAction($context);$context->getState()->handle();$startState = new StopState();$startState->doAction($context);$context->getState()->handle();