flutter cheatsheet

provider

Provider	The most basic form of provider. It takes a value and exposes it, whatever the value is.
ListenableProvider	A specific provider for Listenable object. ListenableProvider will listen to the object and ask widgets which depend on it to rebuild whenever the listener is called.
ChangeNotifierProvider	A specification of ListenableProvider for ChangeNotifier. It will automatically call ChangeNotifier.dispose when needed.
ValueListenableProvider	Listen to a ValueListenable and only expose ValueListenable.value.
StreamProvider	Listen to a Stream and expose the latest value emitted.
FutureProvider	Takes a Future and updates dependents when the future completes.
ListenableProxyProvider	A variation of ListenableProvider that builds its value from values obtained from other providers.
ProxyProvider	A provider that builds a value based on other providers.
snackbar	ScaffoldMessenger. of(context). showSnackBar( SnackBar(       content: const Text('snack'),         duration: const Duration(seconds: 1),      ));
bottomNavigationBar	return Scaffold( appBar: AppBar( title:const Text("sample") ), body: _widgetOptions.elementAt(_selectedIndex), bottomNavigationBar: BottomNavigationBar( items: const [ BottomNavigationBarItem( icon:Icon(Icons.business), label: "Home" ), BottomNavigationBarItem( icon:Icon(Icons.business), label: "Home" ), BottomNavigationBarItem( icon:Icon(Icons.business), label: "Home" ) ], currentIndex: _selectedIndex, selectedItemColor: Colors.amber[800], onTap: _onItemTapped, ), );
WidgetsBindingObserver	class _LifecycleWatcherState extends State<LifecycleWatcher> with WidgetsBindingObserver { AppLifecycleState _lastLifecycleState; @override void initState() { super.initState(); WidgetsBinding.instance.addObserver(this); } @override void dispose() { WidgetsBinding.instance.removeObserver(this); super.dispose(); } @override void didChangeAppLifecycleState(AppLifecycleState state) { setState(() { _lastLifecycleState = state; }); } @override Widget build(BuildContext context) { if (_lastLifecycleState == null) return Text('This widget has not observed any lifecycle changes.', textDirection: TextDirection.ltr); return Text('The most recent lifecycle state this widget observed was: $_lastLifecycleState.', textDirection: TextDirection.ltr); } }

https://medium.com/flutter-korea/row-column-widgets-8c1ff09a6219

https://bsscco.github.io/posts/flutter-introduction-to-animations/