Since an observer needs to be able to access an observable, the observer client can use two primary framework helper classes to make that easier.

因为观察者需要访问被观察目标，观察者客户机可以使用框架提供的两个主要帮助类，来提供更多方便之处。

youdao

Since an observer needs to be able to access an observable, the observer client can use two primary framework helper classes to make that easier.

因为观察者需要访问被观察目标，观察者客户机可以使用框架提供的两个主要帮助类，来提供更多方便之处。

youdao