通过在flutter中删除provider类中的重复条目来更新购物车

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

class CartItem {
  String name;
  double price;
  int quantity;

  CartItem({required this.name, required this.price, required this.quantity});
}

class CartProvider extends ChangeNotifier {
  List<CartItem> _items = [];

  List<CartItem> get items => _items;

  void addItem(CartItem item) {
    _items.add(item);
    notifyListeners();
  }

  void removeItem(CartItem item) {
    _items.remove(item);
    notifyListeners();
  }
}

class ShoppingCartPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Shopping Cart'),
      ),
      body: Consumer<CartProvider>(
        builder: (context, cartProvider, child) {
          return ListView.builder(
            itemCount: cartProvider.items.length,
            itemBuilder: (context, index) {
              final item = cartProvider.items[index];
              return ListTile(
                title: Text(item.name),
                subtitle: Text('Price: \$${item.price}'),
                trailing: IconButton(
                  icon: Icon(Icons.delete),
                  onPressed: () {
                    cartProvider.removeItem(item);
                  },
                ),
              );
            },
          );
        },
      ),
    );
  }
}

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (context) => CartProvider(),
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: ShoppingCartPage(),
    );
  }
}