libPersistence/EstadoPersistente.cs

using System;
using System.IO;
using System.Reflection;
using System.Windows;
using Newtonsoft.Json;

namespace libPersistence
{

    public abstract class EstadoPersistente<T> where T : EstadoPersistente<T>, new()
    {
        private static readonly Lazy<T> instance = new Lazy<T>(() => Load());

        static EstadoPersistente()
        {
            Application.Current.Exit += OnApplicationExit;
        }

        public static T Instance => instance.Value;

        private static string GetFileName()
        {
            var appName = AppDomain.CurrentDomain.FriendlyName;
            var className = typeof(T).Name;
            var folderPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), appName);
            Directory.CreateDirectory(folderPath);
            return Path.Combine(folderPath, $"{className}.json");
        }

        private static T Load()
        {
            var fileName = GetFileName();
            if (File.Exists(fileName))
            {
                var settings = new JsonSerializerSettings
                {
                    TypeNameHandling = TypeNameHandling.Auto,
                    ObjectCreationHandling = ObjectCreationHandling.Replace,
                    // PreserveReferencesHandling = PreserveReferencesHandling.Objects,
                    ConstructorHandling = ConstructorHandling.AllowNonPublicDefaultConstructor
                };
                var jsonString = File.ReadAllText(fileName);
                return JsonConvert.DeserializeObject<T>(jsonString) ?? new T();
            }
            return new T();
        }

        private static void OnApplicationExit(object sender, ExitEventArgs e)
        {
            Instance.Save();
        }

        public void Save()
        {
            var fileName = GetFileName();
            var settings = new JsonSerializerSettings
            {
                Formatting = Formatting.Indented,
                // PreserveReferencesHandling = PreserveReferencesHandling.Objects,
                NullValueHandling = NullValueHandling.Ignore,
                TypeNameHandling = TypeNameHandling.Auto
            };
            // Serializar
            var serializedData = JsonConvert.SerializeObject(this, settings);
            File.WriteAllText(fileName, serializedData);
        }
    }


}