反序列化JSON响应的一部分

Question

我正在使用RESTful JSON API，并尝试使用Newtonsoft的JSON.Net框架反序列化JSON响应消息的PART。

基本上，我收到的响应JSON消息包括头信息以及一组项（Cards）。当我试图反序列化到一个卡列表时，会抛出一个.JsonSerializationException。

我几乎可以肯定这是因为.DeserializeObject方法在标头信息上出错。为了测试这个理论，我"按摩"了JSON响应消息&删除了标头信息；将剩余的JSON保存为字符串&将其传递给Deserialize方法，&成功了！

我的问题是-是否可以向.DeserializeObject方法传递一个参数&强制它ONL反序列化JSON响应的数据组件？

代码：

    public List<Cards.CardResponse> GetByUserToken(string UserToken)
    {
        string requestUrl = URL + "/user/" + UserToken;
        HttpWebRequest request =(HttpWebRequest)WebRequest.Create(requestUrl);
        request.Method = "GET";
        request.ContentType = "application/json";
        String encoded = System.Convert.ToBase64String(System.Text.Encoding.GetEncoding("ISO-8859-1").GetBytes(username + ":" + password));
        request.Headers.Add("Authorization", "Basic " + encoded);
        List<Cards.CardResponse> ReturnCards = null;
        try
        {
            // Get JSON response message
            string jsonResponse = string.Empty;
            HttpWebResponse ws = (HttpWebResponse)request.GetResponse();

            using (System.IO.StreamReader sreader = new System.IO.StreamReader(ws.GetResponseStream()))
            {
                jsonResponse = sreader.ReadToEnd();
            }
            // *** THE LINE BELOW THROWS THE ERROR:
            ReturnCards = (List<Cards.CardResponse>)JsonConvert.DeserializeObject(jsonResponse, typeof(List<Cards.CardResponse>));**
            return ReturnCards;

错误消息：

Newtonsoft.Json.dll 中发生类型为"Newtonsoft.Json.JsonSerializationException"的未处理异常

附加信息：

无法反序列化当前JSON对象（例如｛"name"："value"｝）进入类型'System.Collections.Generic.List`1[ExenseWorks.Marqeta.Cards+CardResponse]'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。

原始JSON:

我还包括了原始的JSON响应——基本上，我想弄清楚如何只从"数据"开始反序列化：

{
    "count": 5,
    "start_index": 0,
    "end_index": 4,
    "is_more": true,
    "data": [{
        "token": "9bd70529-f84a-406e-ad68-eabf69af690f",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "7281",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    },
    {
        "token": "0ec53aef-768d-4499-a661-9e26172b8369",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "5216",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    },
    {
        "token": "82c8b386 -f4b6-40d9-bee6-dd0a5b74d55b",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "6640",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    },
    {
        "token": "1181f23d-b464-4af2-95d9-8b8f48c4d6a8",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "3390",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    },
    {
        "token": "21870467-b059-472e-a130-938356ff1f4a",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "7387",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }]
}

Answer 1

您可以先将其反序列化为JObject，然后提取所需的部分：

var json = JObject.Parse(jsonString);
var partialJsonString = JsonConvert.SerializeObject(json["data"]);
var yourObject = JsonConvert.DeserializeObject<YourType>(partialJsonString );

然而，为所有内容创建类是非常琐碎的：

public class ReplyRoot
{
    public int count { get; set; }
    public int start_index { get; set; }
    public int end_index { get; set; }
    public int is_more { get; set; }
    public DataEntry[] data { get; set; }
}
public class DataEntry
{
    public string token { get; set; }
    // [.. all properties ..]
}
var dto = JsonConvert.DeserializeObject<ReplyRoot>(jsonString);

Answer 2

您可以创建一个新的类来保存整个JSON对象

public class CardResponseWrapper
{
    public int count { get; set; }
    public int startIndex { get; set; }
    public int endIndex { get; set; }
    public bool is_more { get; set; }
    public List<Cards.CardResponse> data { get; set; }
}

然后将请求的结果投射到此对象：

var result = (CardResponseWrapper)JsonConvert.DeserializeObject(jsonResponse, typeof(CardResponseWrapper));

这是您的json格式：

{
    "count": 5,
    "start_index": 0,
    "end_index": 4,
    "is_more": true,
    "data": [{
        "token": "9bd70529-f84a-406e-ad68-eabf69af690f",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "7281",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }, {
        "token": "0ec53aef-768d-4499-a661-9e26172b8369",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "5216",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }, {
        "token": "82c8b386 -f4b6-40d9-bee6-dd0a5b74d55b",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "6640",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }, {
        "token": "1181f23d-b464-4af2-95d9-8b8f48c4d6a8",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "3390",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }, {
        "token": "21870467-b059-472e-a130-938356ff1f4a",
        "pan": "******______****",
        "expiration": "0219",
        "state": "UNACTIVATED",
        "user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
        "card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
        "last_four": "7387",
        "pin_is_set": false,
        "state_reason": "New card",
        "fulfillment_status": "ISSUED"
    }]
}

Answer 3

如果这是您的Json:

{
    n"count": 5,
    n"start_index": 0,
    n"end_index": 4,
    n"is_more": true,
    n"data": [
        {
            n"token": "9bd70529-f84a-406e-ad68-eabf69af690f",
            n"pan": "******______****",
            n"expiration": "0219",
            n"state": "UNACTIVATED",
            n"user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
            n"card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
            n"last_four": "7281",
            n"pin_is_set": false,
            n"state_reason": "Newcard",
            n"fulfillment_status": "ISSUED"n
        },
        {
            n"token": "0ec53aef-768d-4499-a661-9e26172b8369",
            n"pan": "******______****",
            n"expiration": "0219",
            n"state": "UNACTIVATED",
            n"user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
            n"card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
            n"last_four": "5216",
            n"pin_is_set": false,
            n"state_reason": "Newcard",
            n"fulfillment_status": "ISSUED"n
        },
        {
            n"token": "82c8b386-f4b6-40d9-bee6-dd0a5b74d55b",
            n"pan": "******______****",
            n"expiration": "0219",
            n"state": "UNACTIVATED",
            n"user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
            n"card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
            n"last_four": "6640",
            n"pin_is_set": false,
            n"state_reason": "Newcard",
            n"fulfillment_status": "ISSUED"n
        },
        {
            n"token": "1181f23d-b464-4af2-95d9-8b8f48c4d6a8",
            n"pan": "******______****",
            n"expiration": "0219",
            n"state": "UNACTIVATED",
            n"user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
            n"card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
            n"last_four": "3390",
            n"pin_is_set": false,
            n"state_reason": "Newcard",
            n"fulfillment_status": "ISSUED"n
        },
        {
            n"token": "21870467-b059-472e-a130-938356ff1f4a",
            n"pan": "******______****",
            n"expiration": "0219",
            n"state": "UNACTIVATED",
            n"user_token": "2dea06b1-9fc8-423c-bb5b-b733ec895b38",
            n"card_product_token": "dfd110cf-a833-4b21-b7c1-b3bc62b97c52",
            n"last_four": "7387",
            n"pin_is_set": false,
            n"state_reason": "Newcard",
            n"fulfillment_status": "ISSUED"n
        }
    ]n
}

这不是要解析的有效json。您可以在以下位置验证：http://jsonlint.com/