Flutter text- to -speech (Dart语言)：如何在tts引擎阅读文本时为文本添加背景颜色？

import 'package:flutter/material.dart';
import 'package:flutter_tts/flutter_tts.dart';

void main() {
  runApp(MyApp());
}

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

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  FlutterTts flutterTts = FlutterTts();

  @override
  void initState() {
    super.initState();
    flutterTts.setCompletionHandler(() {
      // TTS引擎完成阅读时的回调
    });
  }

  Future speak() async {
    await flutterTts.setLanguage('en-US');
    await flutterTts.setPitch(1.0);
    await flutterTts.setSpeechRate(0.5);

    // 使用RichText来自定义文本样式
    TextSpan textSpan = TextSpan(
      text: 'Hello, world!',
      style: TextStyle(
        backgroundColor: Colors.yellow, // 设置背景颜色
        fontSize: 24,
        fontWeight: FontWeight.bold,
      ),
    );

    await flutterTts.speak(textSpan.toPlainText());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('TTS Demo'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Speak'),
          onPressed: speak,
        ),
      ),
    );
  }
}