Answers for "SnackBar flutter working"

flutter snackbar

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

flutter snackbar replacement

ScaffoldMessenger.of(context).showSnackBar(SnackBar(
  content: const Text('snack'),
  duration: const Duration(seconds: 1),
  action: SnackBarAction(
	label: 'ACTION',
	onPressed: () { },
  ),
));

snackbar in flutter

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