using System;

using System.Collections.Generic;

using System.Reflection;

using Newtonsoft.Json;

using Newtonsoft.Json.Serialization;

public class Program

{

    public static void Main()

    {

        var list = new List<Test>

        {

            new Test { Name = "bytes", Obj = new byte[] { 0x48, 0x65, 0x6c, 0x6c, 0x6f } },

            new Test { Name = "string", Obj = "This is a test" },

            new Test { Name = "reader", Obj = new SqlDataReader() },

            new Test { Name = "decimal", Obj = 3.14159 },

            new Test { Name = "null", Obj = null }

        };

        var settings = new JsonSerializerSettings

        {

            ContractResolver = new AutoIgnoreComplexTypesContractResolver(),

            Formatting = Formatting.Indented

        };

        string json = JsonConvert.SerializeObject(list, settings);

        Console.WriteLine(json);

    }

}

​

public class AutoIgnoreComplexTypesContractResolver : DefaultContractResolver

{

    private static readonly List<Type> IgnoredTypes = new List<Type>()

    {

        typeof(byte[]),

        typeof(SqlDataReader)

    };

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)

    {

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

        if (property.PropertyType == typeof(object))

        {

            property.ShouldSerialize = instance =>

            {

                PropertyInfo pi = member as PropertyInfo;

                object propertyValue = (pi != null) ? pi.GetValue(instance) : null;

                return propertyValue != null && !IgnoredTypes.Contains(propertyValue.GetType());

            };

        }

        else if (IgnoredTypes.Contains(property.PropertyType))

        {

            property.ShouldSerialize = instance => false;

        }

        return property;

    }

}

​

// fake SqlDataReader for demonstration purposes

class SqlDataReader { }

​

class Test

{

    public string Name { get; set; }

    public object Obj { get; set; }

}

​