A utility similar to Compose’s remember, which leverages anlifecycle to let Flutter’s BuildContext remember an instance and provide corresponding management functions.

Usage

1.1 Prepare the lifecycle environment.


class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    // Use LifecycleApp to wrap the default App
    return LifecycleApp(
      child: MaterialApp(
        title: 'Remember Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        navigatorObservers: [
          //Use LifecycleNavigatorObserver.hookMode() to register routing event changes
          LifecycleNavigatorObserver.hookMode(),
        ],
        home: const HomeRememberDemo(title: 'Remember Home Page'),
      ),
    );
  }
}

The current usage of PageView and TabBarViewPageView should be replaced with LifecyclePageView and LifecycleTabBarView. Alternatively, you can wrap the items with LifecyclePageViewItem. You can refer to anlifecycle for guidance.

1.2 Use remember to let the context retain an object.

class HomeRememberDemo extends StatelessWidget {
  final String title;

  const HomeRememberDemo({super.key, required this.title});

  @override
  Widget build(BuildContext context) {
    // 记住一个 ValueNotifier<int> listen:并且自动刷新当前context
    final counter = context.rememberValueNotifier(value: 0, listen: true);
    return Scaffold(
      appBar: AppBar(
        title: Text(title),
      ),
      body: Center(
        child: Text(
          'You have pushed the button this many times: ${counter.value}',
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          counter.value++;
        },
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

Additional information

See anlifecycle

See cancelable

See an_lifecycle_cancellable

Libraries

remember