DART

flutter snackbar

    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
                content: Text("Your Text"),
                duration: Duration(milliseconds: 300),
              ));

flutter snackbar shape

shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20.0)),
behavior: SnackBarBehavior.floating,

flutter dissmis snackbar

ScaffoldMessenger.of(context).hideCurrentSnackBar();

flutter snackbar position

SnackBar(
  behavior: SnackBarBehavior.floating,
  margin: EdgeInsets.only(bottom: 100.0),
  content: Text("Hello World!"),
);

flutter snackbar

final snackBar = SnackBar(
            content: const Text('Yay! A SnackBar!'),
            action: SnackBarAction(
              label: 'Undo',
              onPressed: () {},
            ),
          );
ScaffoldMessenger.of(context).showSnackBar(snackBar);

flutter snackbar top

ScaffoldMessenger.of(context).showSnackBar(new SnackBar(
    content: Text('Snackbar message'),
    behavior: SnackBarBehavior.floating,
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(24),
    ),
    margin: EdgeInsets.only(
        bottom: MediaQuery.of(context).size.height - 100,
        right: 20,
        left: 20),
  ));

snackbar flutter

ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            duration: const Duration(milliseconds: 5000), 
            content: const Text('Awesome Snackbar!'),
          ),
        );

flutter snackbar

final snackBar = SnackBar(
  content: Text('Yay! A SnackBar!'),
  action: SnackBarAction(
    label: 'Undo',
    onPressed: () {
      // Some code to undo the change.
    },
  ),
);

 // Find the Scaffold in the widget tree and use
 // it to show a SnackBar.
 Scaffold.of(context).showSnackBar(snackBar);

snackbar flutter

ScaffoldMessenger.of(context).showSnackBar(SnackBar(
  content: Text('Select car Type first'),
));

snackbar in flutter

final snackBar = SnackBar(content: Text('Yay! A SnackBar!'));

// Find the ScaffoldMessenger in the widget tree
// and use it to show a SnackBar.
ScaffoldMessenger.of(context).showSnackBar(snackBar);

flutter snackbar

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();

  @override
  void initState() {
    super.initState();
    showInSnackBar("Some text");
  }

  @override
  Widget build(BuildContext context) {
    return new Padding(
            key: _scaffoldKey,
            padding: const EdgeInsets.all(16.0),
            child: new Text("Simple Text")
    );
  }

  void showInSnackBar(String value) {
    _scaffoldKey.currentState.showSnackBar(new SnackBar(
        content: new Text(value)
    ));
  }
}

Flutter snackbar top

RaisedButton(
  child: Text('Show Top Snackbar'),
  onPressed: () {
    Flushbar(
      flushbarPosition: FlushbarPosition.TOP,
    )
      ..title = "Hey Ninja"
      ..message = "Lorem Ipsum is simply dummy text of the printing and typesetting industry"
      ..duration = Duration(seconds: 3)
      ..show(context);
  },
),

show snackbar flutter

final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();

void showInSnackBar(String value) {
    _scaffoldKey.currentState.showSnackBar(new SnackBar(content: new Text(value)));
}

snackbar in flutter

final snackBar = SnackBar(
  content: Text('Yay! A SnackBar!'),
  action: SnackBarAction(
    label: 'Undo',
    onPressed: () {
      // Some code to undo the change.
    },
  ),
);