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1 | 1 | import 'package:flutter/material.dart'; |
2 | 2 |
|
3 | 3 | void main() { |
4 | | - runApp(MyApp()); |
| 4 | + runApp(MaterialApp( |
| 5 | + debugShowCheckedModeBanner: false, |
| 6 | + home: HomePage(), |
| 7 | + )); |
5 | 8 | } |
6 | 9 |
|
7 | | -class MyApp extends StatelessWidget { |
8 | | - // This widget is the root of your application. |
| 10 | +class HomePage extends StatefulWidget { |
9 | 11 | @override |
10 | | - Widget build(BuildContext context) { |
11 | | - return MaterialApp( |
12 | | - title: 'Flutter Demo', |
13 | | - theme: ThemeData( |
14 | | - // This is the theme of your application. |
15 | | - // |
16 | | - // Try running your application with "flutter run". You'll see the |
17 | | - // application has a blue toolbar. Then, without quitting the app, try |
18 | | - // changing the primarySwatch below to Colors.green and then invoke |
19 | | - // "hot reload" (press "r" in the console where you ran "flutter run", |
20 | | - // or simply save your changes to "hot reload" in a Flutter IDE). |
21 | | - // Notice that the counter didn't reset back to zero; the application |
22 | | - // is not restarted. |
23 | | - primarySwatch: Colors.blue, |
24 | | - // This makes the visual density adapt to the platform that you run |
25 | | - // the app on. For desktop platforms, the controls will be smaller and |
26 | | - // closer together (more dense) than on mobile platforms. |
27 | | - visualDensity: VisualDensity.adaptivePlatformDensity, |
28 | | - ), |
29 | | - home: MyHomePage(title: 'Flutter Demo Home Page'), |
30 | | - ); |
31 | | - } |
| 12 | + _HomePageState createState() => _HomePageState(); |
32 | 13 | } |
33 | 14 |
|
34 | | -class MyHomePage extends StatefulWidget { |
35 | | - MyHomePage({Key key, this.title}) : super(key: key); |
36 | | - |
37 | | - // This widget is the home page of your application. It is stateful, meaning |
38 | | - // that it has a State object (defined below) that contains fields that affect |
39 | | - // how it looks. |
40 | | - |
41 | | - // This class is the configuration for the state. It holds the values (in this |
42 | | - // case the title) provided by the parent (in this case the App widget) and |
43 | | - // used by the build method of the State. Fields in a Widget subclass are |
44 | | - // always marked "final". |
45 | | - |
46 | | - final String title; |
47 | | - |
48 | | - @override |
49 | | - _MyHomePageState createState() => _MyHomePageState(); |
50 | | -} |
51 | | - |
52 | | -class _MyHomePageState extends State<MyHomePage> { |
53 | | - int _counter = 0; |
54 | | - |
55 | | - void _incrementCounter() { |
56 | | - setState(() { |
57 | | - // This call to setState tells the Flutter framework that something has |
58 | | - // changed in this State, which causes it to rerun the build method below |
59 | | - // so that the display can reflect the updated values. If we changed |
60 | | - // _counter without calling setState(), then the build method would not be |
61 | | - // called again, and so nothing would appear to happen. |
62 | | - _counter++; |
63 | | - }); |
64 | | - } |
65 | | - |
| 15 | +class _HomePageState extends State<HomePage> { |
66 | 16 | @override |
67 | 17 | Widget build(BuildContext context) { |
68 | | - // This method is rerun every time setState is called, for instance as done |
69 | | - // by the _incrementCounter method above. |
70 | | - // |
71 | | - // The Flutter framework has been optimized to make rerunning build methods |
72 | | - // fast, so that you can just rebuild anything that needs updating rather |
73 | | - // than having to individually change instances of widgets. |
74 | 18 | return Scaffold( |
75 | | - appBar: AppBar( |
76 | | - // Here we take the value from the MyHomePage object that was created by |
77 | | - // the App.build method, and use it to set our appbar title. |
78 | | - title: Text(widget.title), |
79 | | - ), |
80 | | - body: Center( |
81 | | - // Center is a layout widget. It takes a single child and positions it |
82 | | - // in the middle of the parent. |
83 | | - child: Column( |
84 | | - // Column is also a layout widget. It takes a list of children and |
85 | | - // arranges them vertically. By default, it sizes itself to fit its |
86 | | - // children horizontally, and tries to be as tall as its parent. |
87 | | - // |
88 | | - // Invoke "debug painting" (press "p" in the console, choose the |
89 | | - // "Toggle Debug Paint" action from the Flutter Inspector in Android |
90 | | - // Studio, or the "Toggle Debug Paint" command in Visual Studio Code) |
91 | | - // to see the wireframe for each widget. |
92 | | - // |
93 | | - // Column has various properties to control how it sizes itself and |
94 | | - // how it positions its children. Here we use mainAxisAlignment to |
95 | | - // center the children vertically; the main axis here is the vertical |
96 | | - // axis because Columns are vertical (the cross axis would be |
97 | | - // horizontal). |
98 | | - mainAxisAlignment: MainAxisAlignment.center, |
99 | | - children: <Widget>[ |
100 | | - Text( |
101 | | - 'You have pushed the button this many times:', |
102 | | - ), |
103 | | - Text( |
104 | | - '$_counter', |
105 | | - style: Theme.of(context).textTheme.headline4, |
106 | | - ), |
107 | | - ], |
108 | | - ), |
109 | | - ), |
110 | | - floatingActionButton: FloatingActionButton( |
111 | | - onPressed: _incrementCounter, |
112 | | - tooltip: 'Increment', |
113 | | - child: Icon(Icons.add), |
114 | | - ), // This trailing comma makes auto-formatting nicer for build methods. |
| 19 | + |
115 | 20 | ); |
116 | 21 | } |
117 | 22 | } |
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