Newtonsoft json反序列化问题 [英] Newtonsoft json deserialisation problem

问题描述

你能协助如何反序化下面的Json字符串吗？

 string JsonString = @{'api_res_key'：'TestKey'，'res_status'：'200'，'res_data'：{'32'：{'state_id'：'32'，'state_name'：' ANDAMAN& NICOBAR'}，'1'：{'state_id'：'1'，'state_name'：'ANDHRA PRADESH'}，'3'：{'state_id'：'3'，'state_name'：'ARUNACHAL PRADESH }}}; 
 JObject person = JObject.Parse（JsonString）; 
 
 我尝试了什么： 
 
我曾尝试以下列方式进行反序列化，但它给了我例外... 
 
 
< pre> public class RootObject 
 {
 public string api_res_key {get;组; } 
 public string res_status {get;组; } 
 public ResData [] res_data {get;组; } 
} 
 
公共类ResData 
 {
 public string state_id {get;组; } 
 public string state_name {get;组; } 
} 

 var Data = JsonConvert.DeserializeObject< RootObject []>（JsonString） ; 

解决方案

您遇到问题的原因是您无法将字典反序列化为列表。



当您查看JSON'res_data'对象时，有3组密钥和&价值对：

'32'：{'state_id'：'32'，'state_name'：'ANDAMAN& NICOBAR'}，
'1'：{'state_id'：'1'，'state_name'：'ANDHRA PRADESH'}，
'3'：{'state_id'：'3'，'state_name '：'ARUNACHAL PRADESH'} 

所以要修复，你需要做类似的事情：

< pre lang =c＃> public class 状态
{
[JsonProperty（ state_id）]
public 字符串 StateId { get ; set ; }

[JsonProperty（ state_name）]
< span class =code-keyword> public string StateName { get ; set ; }
}

public class RootObject
{
[JsonProperty（ api_res_key）]
public string ApiResKey { get ; set ; }

[JsonProperty（ res_status）]
< span class =code-keyword> public string ResStatus { get ; set ; }

[JsonProperty（ res_data）]
< span class =code-keyword> public Dictionary< int，State> ResData { get ; set ; }
}

然后你可以反序列化JSON：

  var  data = JsonHelper.ToClass< RootObject>（JsonString）; 

这里是本文的助手类：在C＃中使用JSON& VB [ ^ ]

  public   static   class  JsonHelper 
 {
  public   static   string  FromClass< T>（T data， bool  isEmptyToNull =  false ，
 JsonSerializerSettings jsonSettings =  null ）
 {
  string  response =  string  .Empty; 
 
  if （！EqualityComparer< T> .Default.Equals（data， default （T）））
 response = JsonConvert.SerializeObject（data，jsonSettings）; 
 
  return  isEmptyToNull？ （response ==   {}？  null：response）：response; 
} 
 
  public   static  T ToClass< T>（< span class =code-keyword> string  data，JsonSerializerSettings jsonSettings =  null ）
 {
  var  response =  default （T）; 
 
  if （！string.IsNullOrEmpty（data））
 response = jsonSettings ==  null  
？ JsonConvert.DeserializeObject< T>（data）
：JsonConvert.DeserializeObject< T>（data，jsonSettings）; 
 
  return 响应; 
} 
} 

Hi,

Can you please assist how to deserialise the below Json string?

string JsonString = @"{'api_res_key':'TestKey','res_status':'200','res_data':{'32':{ 'state_id':'32','state_name':'ANDAMAN & NICOBAR'},'1':{ 'state_id':'1','state_name':'ANDHRA PRADESH'},'3':{ 'state_id':'3','state_name':'ARUNACHAL PRADESH'}}}";
            JObject person = JObject.Parse(JsonString);

What I have tried:

I had tried to deserialise in following way but it gives me exception...


<pre>    public class RootObject
    {
        public string api_res_key { get; set; }
        public string res_status { get; set; }
        public ResData[] res_data { get; set; }
    }

    public class ResData
    {
        public string state_id { get; set; }
        public string state_name { get; set; }
    }

var Data = JsonConvert.DeserializeObject<RootObject[]>(JsonString);

解决方案

The reason that you're having problems is that you can't deserialize a Dictionary into a List.

When you look at the JSON 'res_data' object, there are 3 sets of key & value pairs:

'32':{ 'state_id':'32','state_name':'ANDAMAN & NICOBAR'},
'1' :{ 'state_id':'1','state_name':'ANDHRA PRADESH'},
'3' :{ 'state_id':'3','state_name':'ARUNACHAL PRADESH'}

So to fix, You need to do something like:

public class State
{
    [JsonProperty("state_id")]
    public string StateId { get; set; }

    [JsonProperty("state_name")]
    public string StateName { get; set; }
}

public class RootObject
{
    [JsonProperty("api_res_key")]
    public string ApiResKey { get; set; }

    [JsonProperty("res_status")]
    public string ResStatus { get; set; }

    [JsonProperty("res_data")]
    public Dictionary<int, State> ResData { get; set; }
}

Then you can deserialize the JSON:

var data = JsonHelper.ToClass<RootObject>(JsonString);

And here is the helper class from this article: Working with JSON in C# & VB[^]

public static class JsonHelper
{
    public static string FromClass<T>(T data, bool isEmptyToNull = false,
                                        JsonSerializerSettings jsonSettings = null)
    {
        string response = string.Empty;

        if (!EqualityComparer<T>.Default.Equals(data, default(T)))
            response = JsonConvert.SerializeObject(data, jsonSettings);

        return isEmptyToNull ? (response == "{}" ? "null" : response) : response;
    }

    public static T ToClass<T>(string data, JsonSerializerSettings jsonSettings = null)
    {
        var response = default(T);

        if (!string.IsNullOrEmpty(data))
            response = jsonSettings == null
                ? JsonConvert.DeserializeObject<T>(data)
                : JsonConvert.DeserializeObject<T>(data, jsonSettings);

        return response;
    }
}

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