```dart import 'package:flutter/material.dart'; void main() => runApp(Myapp()); class Myapp extends StatelessWidget{ @override Widget build(BuildContext context) { // TODO: implement build return MaterialApp( title: 'home', home: Scaffold( appBar: AppBar( title: Text('首页'), ), body: Home(), ), theme: ThemeData( primarySwatch:Colors.red // 设置app主题 ), ); } } class Home extends StatelessWidget{ @override Widget build(BuildContext context) { // TODO: implement build return Center( child: Text( '你好', style: TextStyle( fontSize: 40.0, color: Colors.red, backgroundColor: Colors.white ), textDirection: TextDirection.ltr, // 文本从做向右(默认) ), ); } } ```