using System;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        string json = @"

            {

              ""objectNumber"": ""123"",

              ""objectFamily"": ""foo"",

              ""objectOrder"": ""1"",

              ""location"": null,

              ""place"": null,

              ""inventionTime"": null,

              ""lastUpdate"": null,

              ""condition"": null,

              ""Type_X"": null,

              ""actions"": null

            }";     

        var model = JsonConvert.DeserializeObject<JsonModel>(json, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });

        model.Dump();

    }

    public class JsonModel

    {

        public JsonModel()

        {

            Type_X = new Type_X();

            actions = new List<Actions>();

        }

        public string objectNumber { get; set; }

        public string objectFamily { get; set; }

        public string objectOrder { get; set; }

        public string location { get; set; }

        public string place { get; set; }

        public string inventionTime { get; set; }

        public string lastUpdate { get; set; }

        public string condition { get; set; }

​

        public Type_X Type_X { get; set; }

        public List<Actions> actions { get; set; }         

    }

​

    public class Actions

    {

        public string count { get; set; }

        public string datetime { get; set; }

        public string place { get; set; }

        public string status { get; set; }

    }

​

    public class Type_X

    {  

​

        public Type_X()

        {

            partA = "part A default value";

        }

​

        public string partA { get; set; }

        public string PartB { get; set; }

        public string partC { get; set; }

        public string partD { get; set; }

        public string partE { get; set; }

    }   

}