Understanding PageStorageKey in Flutter

PageStorageKey is a tool in Flutter that helps preserve the state of widgets (like scroll position) when navigating between pages or tabs. It works with PageStorage to save and restore widget states, ensuring a smooth user experience.

Why Use PageStorageKey?

Without PageStorageKey, widgets like ListView reset their state (e.g., scroll position) when navigating away and back. PageStorageKey ensures:

• State persistence: Keeps scroll position or input values intact.
• Simplified state management: Reduces the need for complex solutions.

Examples:

class PageStorageExample extends StatelessWidget {
  final PageStorageBucket bucket = PageStorageBucket();

  @override
  Widget build(BuildContext context) {
    return PPageStorage
      bucket: bucket,
      child: ListView.builder(
        key: PageStorageKey('listViewKey'),
        itemCount: 50,
        itemBuilder: (context, index) => ListTile(title: Text('Item $index')),
      ),
    );
  }
}        

TabBarView(
  children: [
    ListView(key: PageStorageKey('tab1'), children: [Text('Tab 1')]),
    ListView(key: PageStorageKey('tab2'), children: [Text('Tab 2')]),
  ],
);        

How It Works

1. PageStorageBucket: Stores widget states.
2. PageStorageKey: Uniquely identifies widgets to persist their state.