Flutter commonly uses keys when it needs to uniquely identify specific widgets within a collection . Using keys also helps Flutter preserve the state of StatefulWidget s while they’re being replaced with other widgets or just moved in the widget tree.
Read moreHow do I rebuild a stateful widget?
The solution is to pass a new Key to WidgetB every time we need it to be rebuilt : WidgetA will see that WidgetB has changed and will rebuild it when setState is called. In other words, whenever a stateful widget’s Key property changes, calling setState on its parent will force a rebuild of the stateful widget.12 Tem 2021
Read moreWhy is the build () method on state and not stateful widget?
Why is the build method on State, and not StatefulWidget? Putting a Widget build(BuildContext context) method on State rather than putting a Widget build(BuildContext context, State state) method on StatefulWidget gives developers more flexibility when subclassing StatefulWidget .
Read moreDoes a new state object is created if the widget rebuild?
The tldr version is that State objects are long lived, but StatefulWidget s (and all Widget subclasses) are thrown away and rebuilt whenever configuration changes .
Read moreWhat is state in stateful widget?
The State is the information that can be read synchronously when the widget is built and might change during the lifetime of the widget.
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