using System;

using System.Linq;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

            {

              ""fs_Unique_Form_Name"": {

                ""title"": ""Title Text"",

                ""description"": ""This is the description."",

                ""code"": ""123""

              },

              ""stackId"": 1,

              ""stateId"": 1,

              ""timeStamp"": ""2020-11-04:10.30.48""

            }";

​

        var response = JsonConvert.DeserializeObject<FormResponse>(json);

        Console.WriteLine("Stack ID: " + response.StackId);

        Console.WriteLine("State ID: " + response.StateId);

        Console.WriteLine("Time Stamp: " + response.TimeStamp);

        Console.WriteLine("Title: " + response.FormDetail.Title);

        Console.WriteLine("Description: " + response.FormDetail.Description);

        Console.WriteLine("Code: " + response.FormDetail.Code);

    }

}

​

public class FormDetail

{

    [JsonProperty(PropertyName = "title")]

    public string Title { get; set; }

​

    [JsonProperty(PropertyName = "description")]

    public string Description { get; set; }

​

    [JsonProperty(PropertyName = "code")]

    public string Code { get; set; }

}

​

[JsonConverter(typeof(FormResponseConverter))]

public class FormResponse

{

    public FormDetail FormDetail { get; set; }

​

    [JsonProperty(PropertyName = "stackId")]

    public int StackId { get; set; }

​

    [JsonProperty(PropertyName = "stateId")]

    public int StateId { get; set; }

​

    [JsonProperty(PropertyName = "timeStamp")]

    public string TimeStamp { get; set; }

}

​

public class FormResponseConverter : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return objectType == typeof(FormResponse);

    }

​

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

    {

        // Load the JSON into a JObject so we can inspect it.

        JObject obj = JObject.Load(reader);

​

        // Populate all the known properties on a new instance of FormResponse.

        FormResponse response = new FormResponse();

        serializer.Populate(obj.CreateReader(), response);

​

        // Now find the first property in the JObject whose name starts with "fs_".

        // If there is one, use it to populate the FormDetail on the response.

        JProperty prop = obj.Properties().FirstOrDefault(p => p.Name.StartsWith("fs_"));

        response.FormDetail = prop != null ? prop.Value.ToObject<FormDetail>(serializer) : null;

​

        return response;

    }

​

    public override bool CanWrite

    {

        get { return false; }

    }

​

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

    {

        throw new NotImplementedException();

    }

}

​