Flutter & Dart，如何在扫描和更新文本时将条形码扫描值传递到TextFormField

dependencies:
  flutter_barcode_scanner: ^2.0.0

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

class BarcodeScannerPage extends StatefulWidget {
  @override
  _BarcodeScannerPageState createState() => _BarcodeScannerPageState();
}

class _BarcodeScannerPageState extends State<BarcodeScannerPage> {
  String _barcodeValue = '';

  Future<void> _scanBarcode() async {
    String barcodeValue = await FlutterBarcodeScanner.scanBarcode(
        '#ff6666', '取消', true, ScanMode.BARCODE);

    setState(() {
      _barcodeValue = barcodeValue;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('条形码扫描'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              '扫描结果:',
              style: TextStyle(fontSize: 20),
            ),
            SizedBox(height: 10),
            Text(
              _barcodeValue,
              style: TextStyle(fontSize: 16),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: _scanBarcode,
              child: Text('扫描条形码'),
            ),
          ],
        ),
      ),
    );
  }
}

Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => BarcodeScannerPage()),
);