实现一个应用基本的布局结构。
举个栗子：
import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget { // This widget is the root of your application. @override Widget build(BuildContext context) { return MaterialApp( theme: ThemeData( primarySwatch: Colors.blue, ), home: new CenterDemoPage() , ); } } class CenterDemoPage extends StatefulWidget { @override createState() =>new CenterDemoPageState(); } class CenterDemoPageState extends State<CenterDemoPage> { @override Widget build(BuildContext context){ return new Scaffold( appBar: new AppBar( title: new Text('Scaffold Widget Demo'), ), body: Center( child: Text('scaffold'), ), bottomNavigationBar: BottomAppBar( child: Container(height: 50.0,), ), floatingActionButton: FloatingActionButton( onPressed: () {}, tooltip: 'Increment', child: Icon(Icons.add), ), floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked, ); } }