C#如何生成含嵌套JArray的JSON并发送至远程服务器？

当前请求发送代码 #

private string SendWebRequest(string url, string requestMethod, string bearer = null, object temp_obj_body = null)
{
    string result = null;
    var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
    httpWebRequest.ContentType = "application/json";
    httpWebRequest.Method = requestMethod.ToUpper();

    // Sets the Security Token
    if (bearer != null)
    {
        httpWebRequest.Headers.Add("Authorization", "Bearer " + bearer);
    }

    //Writes to the request service if body is present
    if (temp_obj_body != null)
    {
        using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream(), Encoding.UTF8))
        {
            JsonSerializerSettings settings = new JsonSerializerSettings();
            settings.CheckAdditionalContent = true;
            settings.Formatting = Formatting.Indented;
            settings.MetadataPropertyHandling = MetadataPropertyHandling.Default;
            settings.NullValueHandling = NullValueHandling.Include;
            settings.PreserveReferencesHandling = PreserveReferencesHandling.All;
            settings.ReferenceLoopHandling = ReferenceLoopHandling.Serialize;
            settings.StringEscapeHandling = StringEscapeHandling.Default;
            settings.TypeNameAssemblyFormatHandling = TypeNameAssemblyFormatHandling.Full;
            settings.TypeNameHandling = TypeNameHandling.All;
            settings.MetadataPropertyHandling = MetadataPropertyHandling.ReadAhead;

            var json = JsonConvert.SerializeObject(temp_obj_body, settings);
            streamWriter.Write(json);
        }
    }

    var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();

    //Reads the response and gets the response.
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        result = streamReader.ReadToEnd();
    }
    return result;
}

当前生成的错误JSON格式 #

{
    "ID": 1,
    "TypeID": 1,
    "UserName": "tempUser",
    "Attributes": "[{\"ID\":13023,\"Value\":\"Nonemp Status\"},
{\"ID\":13022,\"Value\":\"Research Status\"},
{\"ID\":13021,\"Value\":\"ACT\"},
{\"ID\":13024,\"Value\":\"Temp Status\"},
{\"ID\":13025,\"Value\":\"Temp\"}]
}

期望的正确JSON格式 #

{
    "ID": 1,
    "TypeID": 1,
    "UserName": "tempUser",
    "Attributes": [{"ID":13023,"Value":"Nonemp Status"},
{"ID":13022,"Value":"Research Status"},
{"ID":13021,"Value":"ACT"},
{"ID":13024,"Value":"Temp Status"},
{"ID":13025,"Value":"Temp"}]
}

解决方案 #

1. 问题根源 #

你的temp_obj_body对象中，Attributes字段的类型是字符串（string），而非集合类型（如List<T>或JArray）。序列化时字符串会被转义为带引号的JSON字符串，无法被第三方API解析为数组。

2. 具体修复步骤 #

• 定义强类型数据模型
  创建对应的数据类，让Attributes成为集合类型：

  public class RequestBodyModel
  {
      public int ID { get; set; }
      public int TypeID { get; set; }
      public string UserName { get; set; }
      public List<AttributeItem> Attributes { get; set; }
  }
  
  public class AttributeItem
  {
      public int ID { get; set; }
      public string Value { get; set; }
  }
  

• 简化序列化配置
  移除不必要的序列化设置（如TypeNameHandling.All、PreserveReferencesHandling.All），这些配置会生成第三方API不需要的额外字段：

  var settings = new JsonSerializerSettings
  {
      Formatting = Formatting.Indented,
      NullValueHandling = NullValueHandling.Include,
      ReferenceLoopHandling = ReferenceLoopHandling.Ignore // 避免循环引用问题
  };
  

• 构造正确的请求对象
  确保传入的temp_obj_body中，Attributes是集合实例而非字符串：

  var requestBody = new RequestBodyModel
  {
      ID = 1,
      TypeID = 1,
      UserName = "tempUser",
      Attributes = new List<AttributeItem>
      {
          new AttributeItem { ID = 13023, Value = "Nonemp Status" },
          new AttributeItem { ID = 13022, Value = "Research Status" },
          // 添加其他属性项
      }
  };
  
  var response = SendWebRequest(apiUrl, "POST", bearerToken, requestBody);
  

• 若无法修改原始对象类型
  若只能拿到Attributes的字符串形式，先反序列化为集合再替换：

  // 假设temp_obj_body是动态对象或已有类实例
  var attributesStr = temp_obj_body.Attributes.ToString();
  temp_obj_body.Attributes = JsonConvert.DeserializeObject<List<AttributeItem>>(attributesStr);
  

内容的提问来源于stack exchange，提问作者kw2456