appbar design flutter code example

Example 1: flutter appbar widget

Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('AppBar Title', textAlign: TextAlign.center),
      ),

Example 2: appbar theme flutter

appBarTheme: AppBarTheme().copyWith(
          textTheme: TextTheme(
            headline6: TextStyle(
              fontFamily: 'Open Sans',
              fontWeight: FontWeight.bold,
              fontSize: 20,
            ),
          ),
        ),