using System;

using System.Reflection;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

public class Program

{

    public static void Main()

    {

        string inputJson = @"

        {

            ""obj"": {

                ""w"": null,

                ""x"": """",

                ""y"": ""test str"",

                ""Z"": ""N/A""

            },

            ""myStr"": ""Hi""

        }";

​

        var obj = JsonConvert.DeserializeObject<YourClass>(inputJson);

​

        var serializerSettings = new JsonSerializerSettings

        {

            ContractResolver = new CustomContractResolver

            {

                NamingStrategy = new CamelCaseNamingStrategy()

            }

        };

​

        string outputJson = JsonConvert.SerializeObject(obj, serializerSettings);

​

        Console.WriteLine(outputJson);

    }

}

​

class YourClass

{

    public OtherClass Obj { get; set; }

    public string MyStr { get; set; }

}

​

class OtherClass

{

    public string W { get; set; }

    public string X { get; set; }

    public string Y { get; set; }

    public string Z { get; set; }

}

​

class CustomContractResolver : DefaultContractResolver

{

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)

    {

        var prop = base.CreateProperty(member, memberSerialization);

        if (prop.PropertyType == typeof(string) && prop.Readable)

        {

            prop.ShouldSerialize = obj =>

            {

                string val = (string)prop.ValueProvider.GetValue(obj);

                return !string.IsNullOrEmpty(val) && !val.Equals("N/A", StringComparison.OrdinalIgnoreCase);

            };

        }

        return prop;

    }

}

​