Newtonsoft.Json.JsonSerializationException: '无法反序列化当前 JSON 数组

Question

我是 API 的新手，在过去的几天里，我一直在练习使用来自 github 等的预制 API。现在我决定尝试创建自己的冠状病毒追踪应用程序（非常原创）。我已运行进入标题问题，但尚未在网上找到有关如何修复该问题的解决方案。我想我正在尝试接收的 JSON (https://api.covid19api.com/live/country/germany) 是一个数组，我无法让它工作。我在非数组 JSON (reddit's) 上尝试过同样的事情，它就像一个魅力。所有代码和类都粘贴在下面，感谢所有花时间阅读本文并决定提供帮助的人。

Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'Covid.Api.CovidStats' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly. To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array. Path '', line 1, position 1.'

using Newtonsoft.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;


namespace Covid.Api
{


public class CovidClient
{

    public async Task<CovidStats> GetByCountryLiveStats(string country,DateTime startDate,DateTime endDate)
    {
        var url = $"https://api.covid19api.com/country/{country}/status/confirmed/live?from={startDate}&to={endDate}";
        var client = new HttpClient();
        var response = await client.GetStringAsync(url);
        return JsonConvert.DeserializeObject<CovidStats>(response);
        
    }

}

public class CovidStats
{ 
    [JsonProperty("Country")]
    public string Country { get; set; }
    [JsonProperty("Cases")]
    public int Cases { get; set; }
    [JsonProperty("Status")]
    public string Status { get; set; }
    [JsonProperty("Date")]
    public DateTime date { get; set; }
}
public class CovidList
{
    List<CovidStats> lista { get; set; }
}


}

Answer 1

API return 是一个 List 而不是单个对象，因此您需要更新反序列化行：

return JsonConvert.DeserializeObject<List<CovidStats>>(response);

更新：

为了完整性，您还需要更新方法的 return 类型。完整代码如下：

public static async Task<List<CovidStats>> GetByCountryLiveStats(string country, DateTime startDate, DateTime endDate)
{
   var url =  $"https://api.covid19api.com/country/{country}/status/confirmed/live?from= {startDate}&to={endDate}";
   var client = new HttpClient();
   var response = await client.GetStringAsync(url);
   return JsonConvert.DeserializeObject<List<CovidStats>>(response);
}

Answer 2

试试这个

JsonConvert.DeserializeObject<CovidList>(response);

Newtonsoft.Json.JsonSerializationException: '无法反序列化当前 JSON 数组

Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON array

.net

c#

api

console

json