import 'package:flutter/material.dart';class MyApp extends StatelessWidget { @override Widget build(BuildContext context) {  return new Scaffold(   appBar: new AppBar(    title: new Text('底部面板')   ),   body: new Center(    child: new RaisedButton(     child: new Text('顯示底部面板'),     onPressed: () {      // showModalBottomSheet<T>：顯示模態質感設計底部面板      showModalBottomSheet<Null>(context:context, builder:(BuildContext context) {       return new Container(        child: new Padding(         padding: const EdgeInsets.all(32.0),         child: new Text(          '這是模態底部面板，點擊任意位置即可關閉',          textAlign: TextAlign.center,          style: new TextStyle(           color: Theme.of(context).accentColor,           fontSize: 24.0          )         )        )       );      });     }    )   )  ); }}void main() { runApp(new MaterialApp(  title: 'Flutter Demo',  home: new MyApp() ));}