如何从 Flutter 中的状态更改 TextField 值？

我想从其他状态更新 TextField 值，我从父小部件传递（并在 中设置文本initState()）。我的 TextField 小部件设置了一次值，但在状态更新时不会更新。是否可以将 TextField 值与来自父级的状态同步？

更新：

我的文本字段

import 'package:flutter/material.dart';

class MyTextField extends StatefulWidget {
  final hintText;
  final icon;
  final keyboardType;
  final onTap;
  final readOnly;
  final text;

  const MyTextField(
      {this.hintText,
      this.icon,
      this.keyboardType,
      this.onTap,
      this.readOnly,
      this.text});

  @override
  _MyTextFieldState createState() => _MyTextFieldState();
}

class _MyTextFieldState extends State<MyTextField> {
  TextEditingController textController = TextEditingController();
  late FocusNode focusNode = FocusNode();
  Color fieldColor = MidneitColors.silverSand200;

  void _fieldFocusListener() {
    setState(() {
      fieldColor = focusNode.hasFocus
          ? Colors.red
          : Colors.blue;
    });
  }

  @override
  void initState() {
    textController.text = widget.text ?? '';
    super.initState();

    focusNode.addListener(_fieldFocusListener);
  }

  @override
  void dispose() {
    focusNode.removeListener(_fieldFocusListener);

    textController.dispose();
    focusNode.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.all(
              const Radius.circular(10)),
          boxShadow: [
            BoxShadow(
                blurRadius: 15,
                color: Colors.grey,
                spreadRadius: -7,
                offset: const Offset(0, 4))
          ]),
      child: TextFormField(
        controller: textController,
        readOnly: widget.readOnly == null ? false : widget.readOnly,
        focusNode: focusNode,
        keyboardType: widget.keyboardType,
        onTap: widget.onTap,
        decoration: InputDecoration(
          contentPadding: const EdgeInsets.only(left: 20),
          prefixIcon: widget.icon != null
              ? Icon(widget.icon, size: 18, color: fieldColor)
              : null,
          fillColor: Colors.white,
          enabledBorder: OutlineInputBorder(
              borderSide: const BorderSide(color: Colors.grey),
              borderRadius: BorderRadius.all(
                  const Radius.circular(10.0))),
          focusedBorder: const OutlineInputBorder(
              borderSide: const BorderSide(color: Colors.blue),
              borderRadius: const BorderRadius.all(
                  const Radius.circular(10.0))),
          hintText: widget.hintText,
        ),
      ),
    );
  }
}

我的主屏幕

import 'package:flutter/material.dart';

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  String city = 'Mos';

  void onPressed() {
    setState(() {
      city = 'St.Peter';
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: SafeArea(
            child: Container(
      padding: const EdgeInsets.all(20),
      child: ListView(
        children: [
          Form(
              child: Column(
            children: [
              MyTextField(
                  hintText: 'From',
                  onTap: () => onPressed(),
                  readOnly: true,
                  text: city)
            ],
          ))
        ],
      ),
    )));
  }
}