private $strategy = null;
//用于保存策略
/**
* 设置指定的策略
* @param Strategy $strategy
*/
public function setStrategy(Strategy $strategy)
{
$this->strategy = $strategy;
}
/**
* 执行策略的方法
*/
public function index()
{
if (empty($this->strategy)) {
echo 'no stragety';
exit;
}
//执行策略的方法
$this->strategy->algorithmInterface();
}
}
//usage:
$context = new Context();
$strategyA = new StrategyA();
//实例化策略A
$context->setStrategy();
//设置策略A
$context->index();
//执行策略
