using System;

using System.Collections.Generic;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

​

public class Program

{

    public static void Main(string[] args)

    {

        string json = @"

        {

            ""reports"":

            {

                ""report"":

                {

                    ""id"":""1"",

                    ""step"":

                    {

                        ""id"":""2"",

                        ""step"":

                        [

                            {

                                ""id"":""3"",

                                ""step"":

                                [

                                    {

                                        ""id"":""4"",

                                        ""step"":

                                        [

                                            {

                                                ""id"":""8""

                                            },

                                            {

                                                ""id"":""9""

                                            }

                                        ]

                                    },

                                    {

                                        ""id"":""5""

                                    }

                                ]

                            },

                            {

                                ""id"":""6"",

                                ""step"":

                                {

                                    ""id"":""7""

                                }

                            }

                        ]

                    }

                }

            }

        }";

​

        Rootobject reportResult = JsonConvert.DeserializeObject<Rootobject>(json);

​

        json = JsonConvert.SerializeObject(reportResult, Formatting.Indented);

        Console.WriteLine(json);

    }

}

​

​

​

public class Rootobject

{

    public Reports reports { get; set; }

}

​

public class Reports

{

    public Report report { get; set; }

}

​

public class Report

{

    public string id { get; set; }

    public Step step { get; set; }

}

​

​

public class Step

{

    public string id { get; set; }

    [JsonConverter(typeof(SingleOrArrayConverter<Step>))]

    public List<Step> step { get; set; }

}

​

​

​

class SingleOrArrayConverter<T> : JsonConverter

{

    public override bool CanConvert(Type objectType)

    {

        return (objectType == typeof(List<T>));

    }

​

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

    {

        JToken token = JToken.Load(reader);

        if (token.Type == JTokenType.Array)

        {

            return token.ToObject<List<T>>();

        }

        return new List<T> { token.ToObject<T>() };

    }

​

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

    {

        List<T> list = (List<T>)value;

        if (list.Count == 1)

        {

            value = list[0];

        }

        serializer.Serialize(writer, value);

    }

}