如何在Firebase数据库中获取键的值并将其传递给TextField？

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

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  final databaseReference = FirebaseDatabase.instance.reference();

  String keyValue = '';

  @override
  void initState() {
    super.initState();
    // 监听键的值的变化
    databaseReference.child('your_key').onValue.listen((event) {
      setState(() {
        // 获取键的值
        keyValue = event.snapshot.value.toString();
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: TextField(
          controller: TextEditingController(text: keyValue),
          onChanged: (value) {
            // 更新键的值到Firebase数据库
            databaseReference.child('your_key').set(value);
          },
        ),
      ),
    );
  }
}