1_SimpleDialog(对话框)

import 'package:flutter/material.dart';import 'dart:async';void main(){runApp(MaterialApp(home: MyApp(),));}class MyApp extends StatefulWidget {@override_State createState() => _State();}enum Answers{YES,NO,MAYBE}class _State extends State<MyApp>{String _value = '';void _setValue(String value) => setState(() => _value = value);Future _askUser() async {var showDialog2 = showDialog(context: context,child:SimpleDialog(title: Text('开关电源'),children: <Widget>[SimpleDialogOption(child: Text('升压'),onPressed: (){Navigator.pop(context, Answers.YES);},),SimpleDialogOption(child: Text('升降压'),onPressed: (){Navigator.pop(context, Answers.NO);},),SimpleDialogOption(child: Text('降压'),onPressed: (){Navigator.pop(context, Answers.MAYBE);},),],));switch(await showDialog2) {case Answers.YES:_setValue('升压');break;case Answers.NO:_setValue('升降压');break;case Answers.MAYBE:_setValue('降压');break;}}@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text('SimpleDialog'),backgroundColor: Colors.red,),body: Container(child: Center(child: Column(children: <Widget>[Text(_value),RaisedButton(onPressed: _askUser, child: Text('确定'),)],),),),);}}复制代码

2_FloatingActionButton(浮动按钮)

import 'package:flutter/material.dart';void main(){runApp(MaterialApp(home: MyApp(),));}class MyApp extends StatefulWidget {@override_State createState() => _State();}class _State extends State<MyApp>{String _value = '';void _onClicked() => setState(() => _value = DateTime.now().toString());@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text('FloatingActionButton'),backgroundColor: Colors.red,),floatingActionButton: FloatingActionButton(onPressed: _onClicked,backgroundColor: Colors.red,mini: false,child: Icon(Icons.timer),),body: Container(padding: EdgeInsets.all(32.0),child: Center(child: Column(children: <Widget>[Text(_value)],),),),);}}复制代码

3_Slider(滑动器)

import 'package:flutter/material.dart';void main(){runApp(MaterialApp(home: MyApp(),));}class MyApp extends StatefulWidget {@override_State createState() => _State();}class _State extends State<MyApp>{double _value = 0.0;void _setvalue(double value) => setState(() => _value = value);@overrideWidget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text('Slider'),),body: Container(padding: EdgeInsets.all(32.0),child: Center(child: Column(children: <Widget>[Text('值: ${(_value * 100).round()}'),Slider(value: _value, onChanged: _setvalue)],),),),);}}复制代码