php设计模式 策略模式，php设计模式

php设计模式 策略模式，php设计模式

策略模式：

将一组特定的行为和算法封装成类，以适应某些特定的上下文环境；

实际应用举例，假如一个电商网站系统，针对男性女性用户要各自跳转到不同的商品类目，并且所有广告位展示不同的广告。

UserStrategy.php

<?<span>php
namespace Baobab;

</span><span>interface</span><span> UserStrategy{
    </span><span>function</span><span> showAd();
    </span><span>function</span><span> showCategory();
}
</span>?>

FemaleUserStrategy.php

<?<span>php
namespace Baobab;

</span><span>class</span> FemaleUserStrategy <span>implements</span><span> UserStrategy{
    </span><span>function</span><span> showAd(){
        </span><span>echo</span> '2016新款女装'<span>;
    }
    </span><span>function</span><span> showCategory(){
        </span><span>echo</span> '女装'<span>;
    }
}

</span>?>

MaleUserStrategy.php

<?<span>php
namespace Baobab;

</span><span>class</span> MaleUserStrategy <span>implements</span><span> UserStrategy{
    </span><span>function</span><span> showAd(){
        </span><span>echo</span> 'Iphone6s plus'<span>;
    }
    </span><span>function</span><span> showCategory(){
        </span><span>echo</span> '电子产品'<span>;
    }
}

</span>?>

index.php

<span>class</span><span> Page{
     </span><span>protected</span> <span>$strategy</span><span>;
     </span><span>function</span><span> Index(){
         </span><span>$this</span>->strategy-><span>showAd();
         </span><span>echo</span> '<br/>'<span>;
         </span><span>$this</span>->strategy-><span>showCategory();
     }
     </span><span>function</span> setStrategy(Baobab\UserStrategy <span>$strategy</span><span>){
         </span><span>$this</span>->strategy = <span>$strategy</span><span>;
     }
}
</span><span>$page</span> = <span>new</span><span> Page();
</span><span>if</span> (<span>isset</span>(<span>$_GET</span>['female'<span>])){
    </span><span>$strategy</span> = <span>new</span><span> Baobab\FemaleUserStrategy();
}</span><span>else</span><span>{
    </span><span>$strategy</span> = <span>new</span><span> Baobab\MaleUserStrategy();
}
</span><span>$page</span>->setStrategy(<span>$strategy</span><span>);
</span><span>$page</span>->Index();

使用策略模式可实现Ioc，依赖倒置、控制反转