using System;

using System.IO;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var items = new[] {

            new { Name = "John",

                    Age = 5,

                    Address = new { Home = "No. 123, Oak Street", Email = "john@mail.com" },

                    Extra = new { Serials = new[] { 20, 30, 40, 50 } }

            },

            new { Name = "Jean",

                    Age = 2,

                    Address = new { Home = "No. 321, Cliff Road", Email = "jean@mail.com" },

                    Extra = new { Serials = new[] { 25, 35, 45, 55 } }

            }

        };

​

        Console.WriteLine("--- Full indenting ---");

        Console.WriteLine(SerializeWithCustomIndenting(items));

        Console.WriteLine();

        Console.WriteLine("--- 3 levels of indenting ---");

        Console.WriteLine(SerializeWithCustomIndenting(items, 3));

        Console.WriteLine();

        Console.WriteLine("--- 2 levels of indenting ---");

        Console.WriteLine(SerializeWithCustomIndenting(items, 2));

        Console.WriteLine();

        Console.WriteLine("--- 1 level of indenting ---");

        Console.WriteLine(SerializeWithCustomIndenting(items, 1));

        Console.WriteLine();

        Console.WriteLine("--- No indenting ---");

        Console.WriteLine(SerializeWithCustomIndenting(items, 0)); 

        Console.WriteLine();

    }

    public static string SerializeWithCustomIndenting(object obj, int? maxIdentDepth = null)

    {

        using (StringWriter sw = new StringWriter())

            using (CustomIndentingJsonTextWriter jw = new CustomIndentingJsonTextWriter(sw))

        {

            jw.MaxIndentDepth = maxIdentDepth;

            JsonSerializer ser = new JsonSerializer();

            ser.Serialize(jw, obj);

            return sw.ToString();

        }

    }

​

}

​

public class CustomIndentingJsonTextWriter : JsonTextWriter

{

    public int? MaxIndentDepth { get; set; } 

​

    public CustomIndentingJsonTextWriter(TextWriter writer) : base(writer)

    {

        Formatting = Formatting.Indented;

    }

​

    public override void WriteStartArray()

    {

        base.WriteStartArray();

        if (MaxIndentDepth.HasValue && Top > MaxIndentDepth.Value) 

            Formatting = Formatting.None;

    }

​

    public override void WriteStartObject()

    {

        base.WriteStartObject();

        if (MaxIndentDepth.HasValue && Top > MaxIndentDepth.Value) 

            Formatting = Formatting.None;

    }

​

    public override void WriteEndArray()

    {

        base.WriteEndArray();

        if (MaxIndentDepth.HasValue && Top <= MaxIndentDepth.Value) 

            Formatting = Formatting.Indented;

    }

​

    public override void WriteEndObject()

    {

        base.WriteEndObject();

        if (MaxIndentDepth.HasValue && Top <= MaxIndentDepth.Value) 

            Formatting = Formatting.Indented;

    }

}

​