Flutter获取MongoDB产品列表时int与double类型不兼容报错

后端基于Node.js+Express搭建，数据存储在MongoDB中。POST请求提交产品时，客户端Dart的Product类与服务端Mongoose模型配合正常，无报错。但通过GET请求获取产品列表时，catch块抛出**"type int is not a subtype of type double"错误；尝试将Dart类中所有double类型改为int后，又出现"type double is not a subtype of type int"**错误。

GET 请求获取产品列表代码 #

Future<List<Product>> fetchAllProducts(BuildContext context) async {
    final userProvider = Provider.of<UserProvider>(context, listen: false);
    List<Product> productList = [];
    try {
    
      http.Response res = await http.get(Uri.parse('$uri/admin/get-products'),
         
          headers: {
            'Content-Type': 'application/json; charset=UTF-8',
            'x-auth-token': userProvider.user.token,
          });
      httpErrorHandle(
        response: res,
        context: context,
        onSuccess: () {
          for (int i = 0; i < jsonDecode(res.body).length; i++) {
            productList.add(
              Product.fromJson(
                jsonEncode(
                  jsonDecode(res.body)[i],
                ),
              ),
            );
            print(' error in above .add block');
          }
        },
      );
    } catch (e) {
      //error: type int is not a subtype of type double ..
      showSnackBar(context, e.toString());
    }

    return productList;
  }

Dart Product 模型类 #

class Product {
  final String? id;
  final String name;
  final String description;
  final double price;
  final double quantity;
  final String category;
  final List<String> images;

  Product({
    required this.name,
    required this.description,
    required this.price,
    required this.quantity,
    required this.category,
    required this.images,
    this.id,
  });

  Map<String, dynamic> toMap() {
    return <String, dynamic>{
      'id': id,
      'name': name,
      'description': description,
      'price': price,
      'quantity': quantity,
      'category': category,
      'images': images,
    };
  }

  factory Product.fromMap(Map<String, dynamic> map) {
    return Product(
        id: map['_id'],
        name: map['name'] ?? '',
        description: map['description'] ?? '',
        price: map['price'] ?? 0.0,
        quantity: map['quantity'] ?? 0.0,
        category: map['category'] ?? '',
        images: List<String>.from(
          (map['images']),
        ));
  }

  String toJson() => json.encode(toMap());

  factory Product.fromJson(String source) =>
      Product.fromMap(json.decode(source));
}

httpErrorHandle 工具函数 #

void httpErrorHandle({
  required http.Response response,
  required BuildContext context,
  required VoidCallback onSuccess,
}) {
  switch (response.statusCode) {
    case 200:
      onSuccess();
      break;
    case 400:
      showSnackBar(context, jsonDecode(response.body)['msg']);
      break;
    case 500:
      showSnackBar(context, jsonDecode(response.body)['error']);
      break;
    default:
      showSnackBar(context, response.body);
  }
}

内容的提问来源于stack exchange，提问作者mohitnx