using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.Serialization;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("--- Instances list is not in JSON ---");

        DeserializeAndDump("{}");

​

        Console.WriteLine("--- Instances list is null ---");

        DeserializeAndDump(@"{ ""Instances"": null }");

​

        Console.WriteLine("--- Instances list is empty ---");

        DeserializeAndDump(@"{ ""Instances"": [] }");

​

        Console.WriteLine("--- Instances list has an item ---");

        DeserializeAndDump(@"{ ""Instances"": [ { ""Name"": ""ABC"", ""MyProperty"": 4 } ] }");

    }

    static void DeserializeAndDump(string json)

    {

        var dataSettings = JsonConvert.DeserializeObject<DataSettings>(json);

        foreach (var instance in dataSettings.Instances)

        {

            Console.WriteLine($"Name: {instance.Name}, MyProperty: {instance.MyProperty}");

        }

        Console.WriteLine();

    }

}

​

public class DataSettings

{

    public DataSettings()

    {

        Instances = new List<Instance>();

    }

​

    public List<Instance> Instances { get; set; }

​

    [OnDeserialized]

    internal void SetDefaultValuesAfterDeserialization(StreamingContext context)

    {

        if (Instances == null || !Instances.Any())

        {

            Instances = new List<Instance>

            {

                new Instance { Name = "XYZ", MyProperty = 11 }

            };

        }

    }

}

​

public class Instance

{

    public string Name { get; set; }

    public int MyProperty { get; set; }

}

​

​