Flutter学习-提示框

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'flutter study',
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Study'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Button'),
          onPressed: () {
            Navigator.push(
                context, MaterialPageRoute(builder: (context) => SecondPage()));
          },
        ),
      ),
    );
  }
}

class SecondPage extends StatefulWidget {
  @override
  _SecondPageState createState() => _SecondPageState();
}

class _SecondPageState extends State<SecondPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Second Page'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('测试showDialog'),
          onPressed: () async {
            await _neverSatisfied();
            Navigator.of(context).pop(); //退出弹出的对话框时顺带跳回首页
          },
        ),
      ),
    );
  }

  _neverSatisfied() async {
    return showDialog<void>(
        context: context,
        barrierDismissible: false, //必须点击按钮才能退出对话框
        builder: (BuildContext context) {
          return AlertDialog(
            title: Text('Rewind and remember'),
            content: SingleChildScrollView(
              child: ListBody(
                children: <Widget>[Text('ONE'), Text('TWO')],
              ),
            ),
            actions: <Widget>[
              FlatButton(
                child: Text('Regret'),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
            ],
          );
        });
  }
}

运行效果：