LifecycleObserver constructor

LifecycleObserver()

Avoids calling this constructor in build method. Call dispose when it will never be used, e.g. call it in State#dispose.

避免在build方法里调用该构造方法。记得在State#build里调用dispose销毁实例。

Implementation

LifecycleObserver() {
  _cache.add(this);
  WidgetsBinding.instance.addObserver(this);
}