在Android中，使用 EditText 进行文本编辑，那么在Flutter中呢？

TextField 可以实现文本编辑功能

import 'package:flutter/material.dart';

void main() {
  runApp(new SampleApp());
}

class SampleApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Sample App',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new SampleAppPage(),
    );
  }
}

class SampleAppPage extends StatefulWidget {
  SampleAppPage({Key key}) : super(key: key);

  @override
  _SampleAppPageState createState() => new _SampleAppPageState();
}

class _SampleAppPageState extends State<SampleAppPage> {
  String _errorText;

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Sample App"),
      ),
      body: new Center(
        child: new TextField(
          onSubmitted: (String text) {
            setState(() {
              if (!isEmail(text)) {
                _errorText = 'Error: This is not an email';
              } else {
                _errorText = null;
              }
            });
          },
          decoration: new InputDecoration(hintText: "This is a hint", errorText: _getErrorText()),
        ),
      ),
    );
  }

  _getErrorText() {
    return _errorText;
  }

  bool isEmail(String em) {
    String emailRegexp  =
        r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$';

    RegExp regExp = new RegExp(emailRegexp );

    return regExp.hasMatch(em);
  }
}

上面代码可以检测输入的文本是否是 Email 如果不是，将会显示隐藏在下的一段提示文本。