如何在flutter中验证动态创建的窗体？

import 'package:flutter/material.dart';

// 表单验证类
class MyFormValidator {
  String validateName(String value) {
    if (value.isEmpty) {
      return '请输入姓名';
    }
    return null;
  }

  String validateEmail(String value) {
    if (value.isEmpty) {
      return '请输入邮箱';
    }
    if (!value.contains('@')) {
      return '请输入有效的邮箱地址';
    }
    return null;
  }
}

class MyForm extends StatefulWidget {
  @override
  _MyFormState createState() => _MyFormState();
}

class _MyFormState extends State<MyForm> {
  final _formKey = GlobalKey<FormState>();
  final _validator = MyFormValidator();

  String _name;
  String _email;

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: [
          TextFormField(
            decoration: InputDecoration(labelText: '姓名'),
            validator: _validator.validateName,
            onSaved: (value) => _name = value,
          ),
          TextFormField(
            decoration: InputDecoration(labelText: '邮箱'),
            validator: _validator.validateEmail,
            onSaved: (value) => _email = value,
          ),
          RaisedButton(
            child: Text('提交'),
            onPressed: () {
              if (_formKey.currentState.validate()) {
                _formKey.currentState.save();
                // 表单验证通过，可以进行提交操作
                // TODO: 提交表单数据
              }
            },
          ),
        ],
      ),
    );
  }
}

// 使用示例
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('表单验证示例')),
        body: Padding(
          padding: EdgeInsets.all(16.0),
          child: MyForm(),
        ),
      ),
    );
  }
}

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