flutter 中的 state 的依赖关系是什么

Question

I am trying to understand the method didChangeDependencies and according to the definition

It is Called when a dependency of this State object changes.

what do they mean by this. My guess is when properties in the state you manage per screen change. Am I right. Please I would love to understand better.

Answer 1

Try to think of it the same as initState but just a little later.

initstate is called before the state loads its dependencies and for that reason no context is available and you get an error for that if u use context in initstate . However, didChangeDependencies is called just few moments after the state loads its dependencies and context is available at this moment so here you can use context .

Answer 2

In case BuildContext.dependOnInheritedWigetOfExactType called, or in case the widget is been moved inside of the element tree, didChangeDependencies will is always called.