Flutter - 无法将所有 json 数据从 api 响应保存到 Iterable List 编辑：（无法从可迭代列表中获取数据）
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【中文标题】Flutter - 无法将所有 json 数据从 api 响应保存到 Iterable List 编辑：（无法从可迭代列表中获取数据）【英文标题】：Flutter - Can't save all json data to Iterable List from api response EDIT: ( Can't Fetch Data from iterable List) 【发布时间】：2020-04-21 00:04:01 【问题描述】：我有一个返回一些数据的 api。我只需要从 api 获取菜数据。问题是当我从 api 响应中获取数据时，第一道菜数据只保存到 iteratable list。
编辑
我无法从可迭代列表中获取数据
api如下所示
[
"restaurant_name": "Cafe",
"restaurant_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001.jpg",
"table_id": "1",
"table_name": "Table 01",
"branch_name": "Cafe",
"nexturl": "http://snapittapp.snapitt.net/api/menu/10/?org=1010000001&branch_id=1000000001&limit=10&offset=20&lang=en",
"table_menu_list": [
"menu_category": "Salads and Soup",
"menu_category_id": "11",
"menu_category_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/ItemGroup_11.jpg",
"nexturl": "http://snapittapp.snapitt.net/api/menu/20/?org=1010000001&branch_id=1000000001&menuCat=11&limit=10&offset=20&lang=en",
"category_dishes": [
"dish_id": "100000001",
"dish_name": "Spinach Salad",
"dish_price": 7.95,
"dish_image": "http://restaurants.unicomerp.net//images/Restaurant/1010000001/Item/Items/100000001.jpg",
"dish_currency": "SAR",
"dish_calories": 15,
"dish_description": "Fresh spinach, mushrooms, and hard-boiled egg served with warm bacon vinaigrette",
"dish_Availability": true,
"dish_Type": 2,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000001&limit=10&offset=20&lang=en",
"addonCat": [
"addon_category": "Spicy/Non-Spicy",
"addon_category_id": "104",
"addon_selection": 0,
"nexturl": "http://snapittapp.snapitt.net/api/menu/40/?org=1010000001&branch_id=1000000001&menuItem=100000001&menuAddonCat=104&menuAddonselc=0&limit=10&offset=20&lang=en",
"addons": [
"dish_id": "100000032",
"dish_name": "Non Spicy",
"dish_price": 25,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000025.jpg",
"dish_currency": "SAR",
"dish_calories": 15,
"dish_description": "Non Spicy",
"dish_Availability": true,
"dish_Type": 1
]
,
"addon_category": "Add On",
"addon_category_id": "101",
"addon_selection": 1,
"nexturl": "http://snapittapp.snapitt.net/api/menu/40/?org=1010000001&branch_id=1000000001&menuItem=100000001&menuAddonCat=101&menuAddonselc=1&limit=10&offset=20&lang=en",
"addons": [
"dish_id": "100000020",
"dish_name": "fried onions",
"dish_price": 15,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000020.jpg",
"dish_currency": "SAR",
"dish_calories": 10,
"dish_description": "fried onions",
"dish_Availability": true,
"dish_Type": 2
]
]
,
"dish_id": "100000003",
"dish_name": "Traditional New England Seafood Chowder",
"dish_price": 12,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000003.jpg",
"dish_currency": "SAR",
"dish_calories": 30,
"dish_description": "with clams, scallops, and shrimp,",
"dish_Availability": true,
"dish_Type": 1,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000003&limit=10&offset=20&lang=en",
"addonCat": []
,
"dish_id": "100000004",
"dish_name": "Salad Bar Soup",
"dish_price": 5,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000004.jpg",
"dish_currency": "SAR",
"dish_calories": 30,
"dish_description": "Flour Mixed with fresh green leafy vegetables",
"dish_Availability": true,
"dish_Type": 2,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000004&limit=10&offset=20&lang=en",
"addonCat": []
,
"dish_id": "100000005",
"dish_name": "chicken-soup",
"dish_price": 14.89,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000005.jpg",
"dish_id": "100000029",
"dish_name": "Tacos",
"dish_price": 25,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000029.jpg",
"dish_currency": "SAR",
"dish_calories": 225,
"dish_description": "Mexican Street Tacos",
"dish_Availability": true,
"dish_Type": 3,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000029&limit=10&offset=20&lang=en",
"addonCat": []
]
]
]
api中有一个名为addonCat的数据类别，我需要在从响应中获取数据时忽略它并继续下一道菜。
api_model.dart 这是我从 api 的响应中获取数据的地方
class CategoryDishes
final String dishId;
final String dishName;
final double dishPrice;
final String dishImage;
final String dishCurrency;
final double dishCalories;
final String dishDescription;
final bool dishAvailability;
final double dishType;
final String nexturl;
//final List<AddonCat> _addonCat;
CategoryDishes(
this.dishId,
this.dishName,
this.dishPrice,
this.dishImage,
this.dishCurrency,
this.dishCalories,
this.dishDescription,
this.dishAvailability,
this.dishType,
this.nexturl);
factory CategoryDishes.fromJson(Map<String, dynamic> json)
return CategoryDishes(
dishId: json['dish_id'],
dishName: json['dish_name'],
dishPrice: json['dish_price'].toDouble(),
dishImage:
json['dish_image'] ?? Constants.FOOD_PLACEHOLDER_IMAGE_ASSET_URL,
dishCurrency: json['dish_currency'],
dishCalories: json['dish_calories'].toDouble(),
dishDescription: json['dish_description'],
dishAvailability: json['dish_Availability'],
dishType: json['dish_Type'].toDouble(),
nexturl: json['nexturl']);
static Resource<List<CategoryDishes>> get all
return Resource(
url: Constants.FOOD_API_URL,
parse: (response)
final result = json.decode(response.body.toString());
// print(response);
Iterable list = result[0]['table_menu_list'][0]['category_dishes'];
debugPrint("=========== Dish_List ==============\n" + list.toString());
debugPrint("====================================");
return list.map((model) => CategoryDishes.fromJson(model)).toList();
);
web.service.dart
class Resource<T>
final String url;
T Function(Response response) parse;
Resource(this.url, this.parse);
class Webservice
Future<T> load<T>(Resource<T> resource) async
final response = await http.get(resource.url);
if (response.statusCode == 200)
// debugPrint("------D------>\n" + response.body);
return resource.parse(response);
else
throw Exception('Failed to load data!');
main.dart
https://pastebin.com/NuDKYCCD
现在我可以将数据保存到可迭代列表中，但无法从列表中获取数据到卡片元素。 main.dart上方是我获取数据的地方。
如何做到这一点？
编辑
我只能在api中获取dishlist的第一部分，在第一类之后有很多菜品，我需要获取所有菜品并显示到相应的标签，请参阅上面的 api 链接以了解 api 是如何的。
任何建议都会有所帮助。
【问题讨论】：
【参考方案1】：它实际上是在保存数据。但是在使用debugPrint 时，它不会在控制台上打印。
您必须在debugPrint 中提供wrapWidth，这样您才能看到存储在变量中的完整响应。
debugPrint(
"=========== Dish_List ==============\n" + list.toString(),
wrapWidth: 1000,
);
debugPrint("====================================");
我认为这是您面临的问题。
你也可以做漂亮的打印以使其易于理解
debugPrint(
"=========== Dish_List ==============",
);
JsonEncoder encoder = new JsonEncoder.withIndent(' ');
debugPrint('$encoder.convert(list)', wrapWidth: 1000);
debugPrint("====================================");
【讨论】：
@AllwiN 很高兴有帮助。我还用漂亮的字体更新了我的答案。你可以检查一下。 当我试图将数据提取到我的卡片元素时，仍然没有显示任何内容？我究竟做错了什么。这是main.dartpastebin.com/NuDKYCCD，这里我正在获取卡片元素的值。
@AllwiN 我会尝试找出问题所在。但您可能想要更改问题或创建新帖子。以便其他人也可以帮助您。
@AllwiN 我不确定问题出在哪里。但是您可以参考此代码GitHub
我面临一个问题，我无法从api 响应中获取所有数据。只有第一个名为 dish 的数组只有我可以从响应中获取。如何从api中获取所有菜肴？代码与我在问题中发布的代码保持一致。【参考方案2】：
列出所有菜肴
Container(
color: Colors.white,
padding: EdgeInsets.fromLTRB(5, 10, 5, 10),
child: ListView.builder(
itemCount: apiResponse[0]['table_menu_list'][0]['category_dishes'].length,
itemBuilder:(cc,ind)
return ListTile(
title:Text(apiResponse[0]['table_menu_list'][0]['category_dishes'][ind]['dish_name'])
//use other properties as your requirement
);
))
从网络获取日期。我使用本地分配数据！换成自己的方法
void assignData()
apiResponse = [
"restaurant_name": "Cafe",
"restaurant_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001.jpg",
"table_id": "1",
"table_name": "Table 01",
"branch_name": "Cafe",
"nexturl": "http://snapittapp.snapitt.net/api/menu/10/?org=1010000001&branch_id=1000000001&limit=10&offset=20&lang=en",
"table_menu_list": [
"menu_category": "Salads and Soup",
"menu_category_id": "11",
"menu_category_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/ItemGroup_11.jpg",
"nexturl": "http://snapittapp.snapitt.net/api/menu/20/?org=1010000001&branch_id=1000000001&menuCat=11&limit=10&offset=20&lang=en",
"category_dishes": [
"dish_id": "100000001",
"dish_name": "Spinach Salad",
"dish_price": 7.95,
"dish_image": "http://restaurants.unicomerp.net//images/Restaurant/1010000001/Item/Items/100000001.jpg",
"dish_currency": "SAR",
"dish_calories": 15,
"dish_description": "Fresh spinach, mushrooms, and hard-boiled egg served with warm bacon vinaigrette",
"dish_Availability": true,
"dish_Type": 2,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000001&limit=10&offset=20&lang=en",
"addonCat": [
"addon_category": "Spicy/Non-Spicy",
"addon_category_id": "104",
"addon_selection": 0,
"nexturl": "http://snapittapp.snapitt.net/api/menu/40/?org=1010000001&branch_id=1000000001&menuItem=100000001&menuAddonCat=104&menuAddonselc=0&limit=10&offset=20&lang=en",
"addons": [
"dish_id": "100000032",
"dish_name": "Non Spicy",
"dish_price": 25,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000025.jpg",
"dish_currency": "SAR",
"dish_calories": 15,
"dish_description": "Non Spicy",
"dish_Availability": true,
"dish_Type": 1
]
,
"addon_category": "Add On",
"addon_category_id": "101",
"addon_selection": 1,
"nexturl": "http://snapittapp.snapitt.net/api/menu/40/?org=1010000001&branch_id=1000000001&menuItem=100000001&menuAddonCat=101&menuAddonselc=1&limit=10&offset=20&lang=en",
"addons": [
"dish_id": "100000020",
"dish_name": "fried onions",
"dish_price": 15,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000020.jpg",
"dish_currency": "SAR",
"dish_calories": 10,
"dish_description": "fried onions",
"dish_Availability": true,
"dish_Type": 2
]
]
,
"dish_id": "100000003",
"dish_name": "Traditional New England Seafood Chowder",
"dish_price": 12,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000003.jpg",
"dish_currency": "SAR",
"dish_calories": 30,
"dish_description": "with clams, scallops, and shrimp,",
"dish_Availability": true,
"dish_Type": 1,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000003&limit=10&offset=20&lang=en",
"addonCat": []
,
"dish_id": "100000004",
"dish_name": "Salad Bar Soup",
"dish_price": 5,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000004.jpg",
"dish_currency": "SAR",
"dish_calories": 30,
"dish_description": "Flour Mixed with fresh green leafy vegetables",
"dish_Availability": true,
"dish_Type": 2,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000004&limit=10&offset=20&lang=en",
"addonCat": []
,
"dish_id": "100000005",
"dish_name": "chicken-soup",
"dish_price": 14.89,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/1010000001/Item/Items/100000005.jpg",
"dish_id": "100000029",
"dish_name": "Tacos",
"dish_price": 25,
"dish_image": "http://restaurants.unicomerp.net/images/Restaurant/Item/Item_100000029.jpg",
"dish_currency": "SAR",
"dish_calories": 225,
"dish_description": "Mexican Street Tacos",
"dish_Availability": true,
"dish_Type": 3,
"nexturl": "http://snapittapp.snapitt.net/api/menu/30/?org=1010000001&branch_id=1000000001&menuItem=100000029&limit=10&offset=20&lang=en",
"addonCat": []
]
]
];
截图
【讨论】：
谢谢老兄！！..让我试试这个。 cc 和 ind ---> 上下文和索引？？ 这不起作用。问题是数据没有存储到可迭代列表中。 使用 List 列表 tmpList = apiResponse[0]['table_menu_list'][0]['category_dishes'];然后按索引获取【参考方案3】：问题在于，您只对结果和 table_menu_list 中的第一项执行此操作
static Resource<List<CategoryDishes>> get all
return Resource(
url: Constants.FOOD_API_URL,
parse: (response)
final result = json.decode(response.body.toString());
// print(response);
Iterable list = result[0]['table_menu_list'][0]['category_dishes'];
debugPrint("=========== Dish_List ==============\n" + list.toString());
debugPrint("====================================");
return list.map((model) => CategoryDishes.fromJson(model)).toList();
);
解析函数我会这样做
final result = json.decode(response.body.toString());
// print(response);
List<CategoryDishes> list = []
List.from(result).forEach((item) =>
List.from(item['table_menu_list']).forEach((menuItem) =>
List.from(menuItem['category_dishes']).forEach((dish) =>
list.add(CategoryDishes.fromJson(dish))
)
)
);
debugPrint("=========== Dish_List ==============\n" + list.toString());
debugPrint("====================================");
return list;
如果您不想在列表中有重复的菜肴（具有相同 id 的菜肴），您可以使用地图
final result = json.decode(response.body.toString());
// print(response);
Map<String, CategoryDishes> map =
List.from(result).forEach((item) =>
List.from(item['table_menu_list']).forEach((menuItem) =>
List.from(menuItem['category_dishes']).forEach((dish) =>
map[dish['dish_id']] = CategoryDishes.fromJson(dish);
)
)
);
return map.values.toList();
【讨论】：
谢谢。现在我在屏幕上获取所有菜肴数据。以上是关于Flutter - 无法将所有 json 数据从 api 响应保存到 Iterable List 编辑：（无法从可迭代列表中获取数据）的主要内容，如果未能解决你的问题，请参考以下文章
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