using System;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

using System.Collections.Generic;

using System.Linq;

using System.Reflection;

public class Program

{

    // Ramin Bateni

    // This code related to my answer in Stackoverflow 

    // here >> https://stackoverflow.com/questions/26162902/how-can-i-do-json-serializer-ignore-navigation-properties/32797274?noredirect=1#comment104684486_32797274

    public static void Main()

    {

        JsonSerializerSettings settings = new JsonSerializerSettings

            {

                // ContractResolver = new CustomResolver();

                // OR:

                ContractResolver = new CustomResolver(new []

                {

                    // keep Lib property between virtual properties

                    nameof(PC.Libs),

                    // keep Files property between virtual properties

                    nameof(PC.Files)

                }),

                PreserveReferencesHandling = PreserveReferencesHandling.None,

                ReferenceLoopHandling = ReferenceLoopHandling.Ignore,

                Formatting = Formatting.Indented

            };

​

            // -------------------------------------------------------------------

            // Do the serialization and output to the console

            var pc=new PC();

            var json = JsonConvert.SerializeObject(pc, settings);

            Console.WriteLine(json);

        }

​

​

    }

​

    internal class PC

    {

        public int FileFolderId {get;set;}

​

        public virtual ICollection<string> Libs { get; set; }

        public virtual ICollection<string> Books { get; set; }

        public virtual ICollection<string> Files { get; set; }

    }

​

    class CustomResolver : DefaultContractResolver

    {

        private readonly List<string> _namesOfVirtualPropsToKeep=new List<string>(new String[]{});

​

        public CustomResolver()

        {}

​

        public CustomResolver(IEnumerable<string> namesOfVirtualPropsToKeep)

        {

            this._namesOfVirtualPropsToKeep=namesOfVirtualPropsToKeep.Select(x=>x.ToLower()).ToList();

        }

        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)

        {

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

            var propInfo = member as PropertyInfo;

            if (propInfo != null)

            {

                if (propInfo.GetMethod.IsVirtual && !propInfo.GetMethod.IsFinal

                    && !_namesOfVirtualPropsToKeep.Contains(propInfo.Name.ToLower()))

                {

                    prop.ShouldSerialize = obj => false;

                }

            }

            return prop;

        }

}