1_card(卡片)

import 'package:flutter/material.dart';void main() => runApp(MyApp());class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(         home:Scaffold(       appBar: AppBar(title: Text('单行card'),),body: Container(  child: Column(    crossAxisAlignment: CrossAxisAlignment.stretch,    children: 
    
     [      CardSaya(icon: Icons.home,teks: "HONE",warnaIcon: Colors.brown,),      CardSaya(icon: Icons.favorite,teks: "favorite",warnaIcon: Colors.pink,),      CardSaya(icon: Icons.place,teks: "place",warnaIcon: Colors.blue,),       CardSaya(icon: Icons.settings,teks: "HONE",warnaIcon: Colors.black,),    ],  ),),    ),    );   }}class CardSaya extends StatelessWidget{  CardSaya({
   this.icon,this.teks,this.warnaIcon});  final IconData icon;  final String teks;  final Color warnaIcon;  @override  Widget build(BuildContext context){    return Container(padding: EdgeInsets.all(10.0),child: Card(  child: Column(    children: 
     
      [      Icon(icon,color: warnaIcon),      Text(teks),    ],  ),),    );  }}复制代码
     
    

2_计算器

---

import 'package:flutter/material.dart';void main() => runApp(MyApp());class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(      theme: ThemeData(primarySwatch: Colors.red),      home: HomePage(),    );  }}class HomePage extends StatefulWidget {  @override  State createState() => HomePageState();}class HomePageState extends State
    
      {  var num1 = 0, num2 = 0, sum = 0;  final TextEditingController t1 = TextEditingController(text: "0");  final TextEditingController t2 = TextEditingController(text: "0");  void doAddition() {    setState(() {      num1 = int.parse(t1.text);      num2 = int.parse(t2.text);      sum = num1 + num2;    });  }  void doSub() {    setState(() {      num1 = int.parse(t1.text);      num2 = int.parse(t2.text);      sum = num1 - num2;    });  }  void doMul() {    setState(() {      num1 = int.parse(t1.text);      num2 = int.parse(t2.text);      sum = num1 * num2;    });  }  void doDiv() {    setState(() {      num1 = int.parse(t1.text);      num2 = int.parse(t2.text);      sum = num1 ~/ num2;    });  }  void doClear() {    setState(() {      t1.text = "0";      t2.text = "0";    });  }  @override  Widget build(BuildContext context) {    return Scaffold(       resizeToAvoidBottomPadding: false,      appBar: AppBar(        title: Text("计算器"),      ),      body: SingleChildScrollView(        padding: const EdgeInsets.all(40.0),        child: Column(          mainAxisAlignment: MainAxisAlignment.center,          children: 
     
      [            Text(              "输出: $sum",              style: TextStyle(                  fontSize: 20.0,                  fontWeight: FontWeight.bold,                  color: Colors.purple),            ),            TextField(              keyboardType: TextInputType.number,              decoration: InputDecoration(hintText: "请输入"),              controller: t1,            ),            TextField(              keyboardType: TextInputType.number,              decoration: InputDecoration(hintText: "请输入"),              controller: t2,            ),            Padding(              padding: const EdgeInsets.only(top: 20.0),            ),            Row(              mainAxisAlignment: MainAxisAlignment.spaceEvenly,              children: 
      
       [                MaterialButton(                  child: Text("+"),                  color: Colors.greenAccent,                  onPressed: doAddition,                ),                MaterialButton(                  child: Text("-"),                  color: Colors.greenAccent,                  onPressed: doSub,                ),              ],            ),            Padding(              padding: const EdgeInsets.only(top: 20.0),            ),            Row(              mainAxisAlignment: MainAxisAlignment.spaceEvenly,              children: 
       
        [                MaterialButton(                  child: Text("*"),                  color: Colors.greenAccent,                  onPressed: doMul,                ),                MaterialButton(                  child: Text("/"),                  color: Colors.greenAccent,                  onPressed: doDiv,                ),              ],            ),            Padding(              padding: const EdgeInsets.only(top: 20.0),            ),            Row(              mainAxisAlignment: MainAxisAlignment.center,              children: 
        
         [                MaterialButton(                  child: Text("清0"),                  color: Colors.greenAccent,                  onPressed: doClear,                ),              ],            )          ],        ),      ),    );  }}复制代码
        
       
      
     
    

3_状态栏隐藏

---

import 'package:flutter/material.dart';import 'package:flutter/services.dart';void main(){   SystemChrome.setEnabledSystemUIOverlays([]);  runApp( MyApp());}class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(      home: Scaffold(        appBar: AppBar(          title:  Text('隐藏状态栏'),        ),        body: Center(          child: Text('隐藏状态栏'),        ),      ),    );  }}复制代码

3.1_隐藏状态栏不隐藏按键栏

import 'package:flutter/material.dart';import 'package:flutter/services.dart';void main(){   SystemChrome.setEnabledSystemUIOverlays([SystemUiOverlay.bottom]);  runApp( MyApp());}class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(      home: Scaffold(        appBar: AppBar(          title:  Text('隐藏状态栏不隐藏按键栏'),        ),        body: Center(          child: Text('隐藏状态栏不隐藏按键栏'),        ),      ),    );  }}复制代码

3.2_导航栏和状态栏颜色

import 'package:flutter/material.dart';import 'package:flutter/services.dart';void main(){    SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle(    systemNavigationBarColor: Colors.blue,    statusBarColor: Colors.pink,  ));  runApp( MyApp());}class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(      home: Scaffold(        appBar: AppBar(          title:  Text('Hello flutter'),        ),        body: Center(          child: Text('Hello flutter'),        ),      ),    );  }}复制代码

3.3_安全区

import 'package:flutter/material.dart';void main()=>runApp( MyApp());class MyApp extends StatelessWidget {  @override  Widget build(BuildContext context) {    return MaterialApp(      home: Scaffold(        body: SafeArea(          child: SizedBox.expand(        child: Card(color: Colors.yellowAccent),      ),        ),        ),      );  }}复制代码