C#中反序列化嵌套JSON数组的问题

Question

编辑我注意到这得到了反对票，我想这是因为没有展示研究成果。我看过很多堆栈溢出的帖子。我找不到一个如此嵌套的JSON示例，该示例已被访问，并提供了存储在JSON中的数据后来如何被操作的示例。

问题和目标

使用restsharp，我收到了对API调用的JSON响应，但我很难对得到的响应进行反序列化。我想要使用的数据似乎是一个嵌套数组（如下）。

然后，我的目标是将该数组的内容传递给一个变量，检查它是否已填充，获取该数组的第一个项，然后将该项中的属性设置为等于数据库中的对象。

这是我用当前代码得到的错误消息。我似乎把Hit对象视为错误类型的对象，但在我的头撞到墙上几个小时后，我不完全确定为什么这对这个特定的JSON结构不起作用。

当前代码

                    var hitresult = JsonConvert.DeserializeObject( response.Content, typeof( List<Hit> ) ) as List<Hit>;
                    if (hitresult.Any())
                    {
                            var address = hitresult.FirstOrDefault();
                            verified = true;
                            result = string.Format( "UDPRN: {0}", address.udprn ); 
                            location.Street1 = address.line_1;
                            location.Street2 = address.line_2;
                            location.City = address.post_town;
                            location.State = address.county;
                            location.PostalCode = address.postcode;

错误消息

"Newtonsoft.Json.JsonSerializationException"类型的异常发生在Newtonsoft.Json.dll中，但未在用户代码中处理

附加信息：无法反序列化当前JSON对象（例如｛"name"："value"｝）转换为类型'System.Collections.Generic.List`1[org.hopecorby.LocationService.Hit]'因为该类型需要JSON数组（例如[1，2，3]）来反序列化正确地

要修复此错误，请将JSON更改为JSON数组（例如。[1，2，3]）或更改反序列化的类型，使其成为正常的.NET类型（例如，不是像integer这样的基元类型，不是集合类型像数组或列表），可以从JSON对象反序列化。JsonObjectAttribute也可以添加到类型中，以强制它从JSON对象反序列化。

路径"result"，第1行，位置10。

JSON示例

 {
    "result": {
        "total": 2,
        "limit": 10,
        "page": 0,
        "hits": [
            {
                "dependant_locality": "",
                "postcode_type": "L",
                "po_box": "",
                "post_town": "LONDON",
                "delivery_point_suffix": "1A",
                "double_dependant_locality": "",
                "su_organisation_indicator": " ",
                "longitude": -0.127695242183412,
                "department_name": "",
                "district": "Westminster",
                "building_name": "",
                "dependant_thoroughfare": "",
                "northings": 179951,
                "premise": "10",
                "postcode_outward": "SW1A",
                "postcode_inward": "2AA",
                "sub_building_name": "",
                "eastings": 530047,
                "postcode": "SW1A 2AA",
                "country": "England",
                "udprn": 23747771,
                "line_3": "",
                "organisation_name": "Prime Minister & First Lord Of The Treasury",
                "ward": "St James's",
                "county": "",
                "line_1": "Prime Minister & First Lord Of The Treasury",
                "building_number": "10",
                "thoroughfare": "Downing Street",
                "line_2": "10 Downing Street",
                "latitude": 51.5035398826274
            },
            {
                "dependant_locality": "",
                "postcode_type": "S",
                "po_box": "",
                "post_town": "LONDON",
                "delivery_point_suffix": "1B",
                "double_dependant_locality": "",
                "su_organisation_indicator": " ",
                "longitude": -0.122624730080001,
                "department_name": "",
                "district": "Camden",
                "building_name": "Downing Court",
                "dependant_thoroughfare": "",
                "northings": 182178,
                "premise": "Flat 10, Downing Court",
                "postcode_outward": "WC1N",
                "postcode_inward": "1LX",
                "sub_building_name": "Flat 10",
                "eastings": 530342,
                "postcode": "WC1N 1LX",
                "country": "England",
                "udprn": 26245117,
                "line_3": "Grenville Street",
                "organisation_name": "",
                "ward": "Bloomsbury",
                "county": "",
                "line_1": "Flat 10",
                "building_number": " ",
                "thoroughfare": "Grenville Street",
                "line_2": "Downing Court",
                "latitude": 51.5234851731108
            }
        ]
    },
    "code": 2000,
    "message": "Success"
}

我的模型（使用json2charp创建）

public class Hit
{
    public string dependant_locality { get; set; }
    public string postcode_type { get; set; }
    public string po_box { get; set; }
    public string post_town { get; set; }
    public string delivery_point_suffix { get; set; }
    public string double_dependant_locality { get; set; }
    public string su_organisation_indicator { get; set; }
    public double longitude { get; set; }
    public string department_name { get; set; }
    public string district { get; set; }
    public string building_name { get; set; }
    public string dependant_thoroughfare { get; set; }
    public int northings { get; set; }
    public string premise { get; set; }
    public string postcode_outward { get; set; }
    public string postcode_inward { get; set; }
    public string sub_building_name { get; set; }
    public int eastings { get; set; }
    public string postcode { get; set; }
    public string country { get; set; }
    public int udprn { get; set; }
    public string line_3 { get; set; }
    public string organisation_name { get; set; }
    public string ward { get; set; }
    public string county { get; set; }
    public string line_1 { get; set; }
    public string building_number { get; set; }
    public string thoroughfare { get; set; }
    public string line_2 { get; set; }
    public double latitude { get; set; }
}
public class Result
{
    public int total { get; set; }
    public int limit { get; set; }
    public int page { get; set; }
    public List<Hit> hits { get; set; }
}
public class RootObject
{
    public Result result { get; set; }
    public int code { get; set; }
    public string message { get; set; }
}

Answer 1

反序列化程序需要一个JSON数组。您的JSON是一个包含JSON数组的JSON对象。反序列化程序不可能知道您希望它开始使用hits数组。

您需要反序列化为RootObject。然后，您就可以将List<Hit>作为Result的属性进行引用。

更新：

下面的代码应该让你明白我的意思。我测试了这一点，它对我来说很有效，包括你的对象和JSON。

var sr = new StreamReader(@"C:UsersdanielcDocumentsVisual Studio 2012ProjectsTestJSONTestJSONresponse.json");
string json = sr.ReadToEnd();
sr.Close();
var root = JsonConvert.DeserializeObject<RootObject>(json);
var result = root.result;
var hits = result.hits;
if (hits.Any())
{
    var address = hits.FirstOrDefault();
    var udprn = string.Format("UDPRN: {0}", address.udprn);
    Console.WriteLine(udprn);
}
Console.Read();