探索Dartea：Flutter开发的MVU模式新星

import 'package:flutter/material.dart';
import 'package:dart_e_shopee/business_logic/util/form_validator.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
 
class SignUpPage extends ConsumerStatefulWidget {
  const SignUpPage({Key? key}) : super(key: key);
 
  @override
  _SignUpPageState createState() => _SignUpPageState();
}
 
class _SignUpPageState extends ConsumerState<SignUpPage> {
  final _formKey = GlobalKey<FormState>();
  var _email = '';
  var _password = '';
  var _confirmPassword = '';
  var _isLoading = false;
 
  void _submit() {
    if (_formKey.currentState!.validate()) {
      _formKey.currentState!.save();
      // 执行注册逻辑
    }
  }
 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Sign Up'),
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : Padding(
              padding: const EdgeInsets.all(16.0),
              child: Form(
                key: _formKey,
                child: Column(
                  children: [
                    TextFormField(
                      decoration: const InputDecoration(labelText: 'Email'),
                      validator: FormValidator.validateEmail,
                      onSaved: (value) => _email = value!,
                    ),
                    const SizedBox(height: 10),
                    TextFormField(
                      decoration: const InputDecoration(labelText: 'Password'),
                      obscureText: true,
                      validator: FormValidator.validatePassword,
                      onSaved: (value) => _password = value!,
                    ),
                    const SizedBox(height: 10),
                    TextFormField(
                      decoration: const InputDecoration(labelText: 'Confirm Password'),
                      obscureText: true,
                      validator: (value) => FormValidator.validateConfirmPassword(_password, value!),
                      onSaved: (value) => _confirmPassword = value!,
                    ),
                    const SizedBox(height: 10),