using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Formatting;

using System.ComponentModel;    

public class Program

{

    public static void Main()

    {

        string json = @"

            {

              ""objectNumber"": null

            }";     

        var model = JsonConvert.DeserializeObject<JsonModel>(json,

    Formatting.Indented,

    new JsonSerializerSettings { DefaultValueHandling = DefaultValueHandling.Ignore });

        model.Dump();

    }

    public class JsonModel

    {

        // [JsonProperty("objectNumber", NullValueHandling = NullValueHandling.Ignore)]

        [DefaultValue(1)]

        public int objectNumber { get; set; }

    }

​

}