Flutter RadioListTile 带标签的单选按钮

带标签的单选按钮

/// Flutter code sample for RadioListTile

// ![RadioListTile sample](https://flutter.github.io/assets-for-api-docs/assets/material/radio_list_tile.png)
//
// This widget shows a pair of radio buttons that control the `_character`
// field. The field is of the type `SingingCharacter`, an enum.

import 'package:flutter/material.dart';

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

/// This is the main application widget.
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const MyStatefulWidget(),
      ),
    );
  }
}

enum SingingCharacter { lafayette, jefferson }

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

/// This is the private State class that goes with MyStatefulWidget.
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  SingingCharacter? _character = SingingCharacter.lafayette;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        RadioListTile<SingingCharacter>(
          title: const Text('Lafayette'),
          value: SingingCharacter.lafayette,
          groupValue: _character,
          onChanged: (SingingCharacter? value) {
            setState(() {
              _character = value;
            });
          },
        ),
        RadioListTile<SingingCharacter>(
          title: const Text('Thomas Jefferson'),
          value: SingingCharacter.jefferson,
          groupValue: _character,
          onChanged: (SingingCharacter? value) {
            setState(() {
              _character = value;
            });
          },
        ),
      ],
    );
  }
}