ASP.NET MVC 核心消费 Web API 与数组？

Question

我遇到了困难，虽然我彻底（我认为）研究了网络，包括在 SO 处，但我似乎找不到我要找的东西——或者我很迟钝。我的环境是.NET6，ASP.NET Core MVC.

我从 API 中成功获取 Json 后遇到的错误是：

JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[ConsumeWebApi.Models.Weather+Root]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object. Path 'region', line 1, position 10.

这对我来说似乎很简单，所以我检查了返回的字符串。

{
    "region": "My Town, ST",
    "currentConditions": {
        "dayhour": "Tuesday 9:00 AM",
        "temp": {
            "c": 14,
            "f": 58
        },
        "precip": "15%",
        "humidity": "72%",
        "wind": {
            "km": 3,
            "mile": 2
        },
        "iconURL": "https://ssl.gstatic.com/onebox/weather/64/sunny.png",
        "comment": "Sunny"
    },
    "next_days": [
        {
            "day": "Tuesday",
            "comment": "Scattered showers",
            "max_temp": {
                "c": 24,
                "f": 75
            },
            "min_temp": {
                "c": 14,
                "f": 58
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/rain_s_cloudy.png"
        },
        {
            "day": "Wednesday",
            "comment": "Scattered showers",
            "max_temp": {
                "c": 17,
                "f": 62
            },
            "min_temp": {
                "c": 9,
                "f": 49
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/rain_s_cloudy.png"
        },
        {
            "day": "Thursday",
            "comment": "Mostly cloudy",
            "max_temp": {
                "c": 22,
                "f": 71
            },
            "min_temp": {
                "c": 12,
                "f": 54
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/partly_cloudy.png"
        },
        {
            "day": "Friday",
            "comment": "Rain",
            "max_temp": {
                "c": 17,
                "f": 62
            },
            "min_temp": {
                "c": 12,
                "f": 53
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/rain.png"
        },
        {
            "day": "Saturday",
            "comment": "Showers",
            "max_temp": {
                "c": 16,
                "f": 60
            },
            "min_temp": {
                "c": 8,
                "f": 46
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/rain_light.png"
        },
        {
            "day": "Sunday",
            "comment": "Partly cloudy",
            "max_temp": {
                "c": 19,
                "f": 66
            },
            "min_temp": {
                "c": 7,
                "f": 45
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/partly_cloudy.png"
        },
        {
            "day": "Monday",
            "comment": "Partly cloudy",
            "max_temp": {
                "c": 22,
                "f": 72
            },
            "min_temp": {
                "c": 9,
                "f": 48
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/partly_cloudy.png"
        },
        {
            "day": "Tuesday",
            "comment": "Mostly sunny",
            "max_temp": {
                "c": 26,
                "f": 79
            },
            "min_temp": {
                "c": 13,
                "f": 55
            },
            "iconURL": "https://ssl.gstatic.com/onebox/weather/48/partly_cloudy.png"
        }
    ],
    "contact_author": {
        "email": "communication.with.users@gmail.com",
        "auth_note": "Mail me for feature requests, improvement, bug, help, ect... Please tell me if you want me to provide any other free easy-to-use API services"
    },
    "data_source": "https://www.google.com/search?lr=lang_en&q=weather+in+mycity+state"
}

我看到的唯一数组是“next_days”，但正如您在下面的数据模型中看到的那样，我考虑到了这一点。我的模型是由 Visual Studio 中的“粘贴 Json 为类”功能创建的，是：

namespace ConsumeWebApi.Models
{
    public class Weather
    {

        public class Root
        {
            public string? Region { get; set; }
            public Currentconditions? CurrentConditions { get; set; }
            public Next_Days[]? Next_days { get; set; }
            public Contact_Author? Contact_author { get; set; }
            public string? Data_source { get; set; }
        }

        public class Currentconditions
        {
            public string? Dayhour { get; set; }
            public Temp? Temp { get; set; }
            public string? Precip { get; set; }
            public string? Humidity { get; set; }
            public Wind? Wind { get; set; }
            public string? IconURL { get; set; }
            public string? Comment { get; set; }
        }

        public class Temp
        {
            public int? C { get; set; }
            public int? F { get; set; }
        }

        public class Wind
        {
            public int? Km { get; set; }
            public int? Mile { get; set; }
        }

        public class Contact_Author
        {
            public string? Email { get; set; }
            public string? Auth_note { get; set; }
        }

        public class Next_Days
        {
            public string? Day { get; set; }
            public string? Comment { get; set; }
            public Max_Temp? Max_temp { get; set; }
            public Min_Temp? Min_temp { get; set; }
            public string? IconURL { get; set; }
        }

        public class Max_Temp
        {
            public int? C { get; set; }
            public int? F { get; set; }
        }

        public class Min_Temp
        {
            public int? C { get; set; }
            public int? F { get; set; }
        }


    }
}

让我们看看我的控制器。（这是我怀疑我不太明白的地方。这里或我的模型。）

        public async Task<IActionResult> Index()
        {
            List<Weather.Root> weatherInfo = new List<Weather.Root>();
            using (var httpClient = new HttpClient())
            {
                using (var response = await httpClient.GetAsync("https://weatherdbi.herokuapp.com/data/weather/mycity+state"))
                {
                    string? apiResponse = await response.Content.ReadAsStringAsync();
                    weatherInfo = JsonConvert.DeserializeObject<List<Weather.Root>>(apiResponse);
                }
            }
            return View(weatherInfo);
        }

Visual Studio 中的调试显示 apiResponse 具有我在上面发布的 Json 数据 - 找不到额外的方括号 []。

对于这个粗略的问题，我深表歉意，并提前感谢您的回复。我是 C# 的新手，但不是 Web 开发的新手。

Answer 1

根是对象，不是集合。所以只使用这个代码

 weatherInfo = JsonConvert.DeserializeObject<Weather.Root>(apiResponse);

Answer 2

解决“Cannot deserialize the current JSON array (e.g. [1,2,3])” 按照以下步骤操作：

使用在线转换器将 JSON 转换为 C#（例如 https://json2csharp.com/）。
将您的 JSON 粘贴到 JSON 部分并生成 C#。
它将生成代码并为您提供反序列化的方法。例如JsonDataService myData = JsonConvert.DeserializeObject(JSON); //JSON 解析

ASP.NET MVC 核心消费 Web API 与数组？

ASP.NET MVC Core Consuming Web API with Arrays?

.net

c#

json

asp.net-core-mvc