using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Diagnostics;

using System.IO;

using System.Threading;

using System.Collections.ObjectModel;

using System.Reflection;

using System.Runtime.Serialization;

using System.Data;

using System.ComponentModel;

using System.Globalization;

using System.Runtime.Serialization.Formatters.Binary;

using System.Collections.Specialized;

using System.Web.Routing;

using System.Net.Mail;

using System.Runtime.InteropServices;

using System.Text.RegularExpressions;

using System.Net;

using System.Dynamic;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;

using System.Web.SessionState;

​

    // https://stackoverflow.com/questions/42863644/ignore-expandoobject-properties-with-json-net-serializer-settings

​

    public class FilteredExpandoObjectConverter : ExpandoObjectConverter

    {

        public override bool CanWrite { get { return true; } }

​

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

        {

            var expando = (IDictionary<string, object>)value;

            var dictionary = expando

                .Where(p => !(p.Value is System.Delegate))

                .ToDictionary(p => p.Key, p => p.Value);

            serializer.Serialize(writer, dictionary);

        }

    }

​

    public class TestClass

    {

        public string TestClassValue { get; set; }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();            

            dynamic subExpando = new ExpandoObject();

            subExpando.func = (Action)(() => {});

            subExpando.list = Enumerable.Range(0, 3).ToList();

            subExpando.query = Enumerable.Range(0, 3);

            subExpando.foo = "bar";

            subExpando.testClass = new TestClass { TestClassValue = "TestClass Value" };

            dynamic expando = new ExpandoObject();

            expando.subExpandoList = new object [] { subExpando };

            expando.func = (Action)(() => {Console.WriteLine("hello");});

            expando.time = DateTime.Today;

            var formatting = Formatting.Indented;

            var serializerSettings = new JsonSerializerSettings

            {

                Converters = { new FilteredExpandoObjectConverter() },

            };

            var json = JsonConvert.SerializeObject(expando, formatting, serializerSettings);

            Console.WriteLine("Filtered expando: ");

            Console.WriteLine(json);

            Console.WriteLine("Unfiltered expando: ");

            try

            {

                Console.WriteLine(JsonConvert.SerializeObject(expando, Formatting.Indented));

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed to serialize unfiltered expando: " + ex.Message);

            }

        }

    }

​