using System;

using System.Collections.Generic;

using System.Reflection;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var myService = new MyService();

        myService.AddToDictionary((new Model() { FirstName = "Joe", LastName = "Doe" }).GetType());

        myService.DisplayDictionary();

    }

    public class MyService

    {

        private static readonly IDictionary<Type, ICollection<PropertyInfo>> _propertyDictionary = new Dictionary<Type, ICollection<PropertyInfo>>();

        public void AddToDictionary(Type type)

        {

            ICollection<PropertyInfo> properties;

            if (!_propertyDictionary.TryGetValue(type, out properties))

            {

                properties = type.GetProperties().ToList();

                _propertyDictionary.Add(type, properties);

            }

        }

        public void DisplayDictionary()

        {

            Console.Write(_propertyDictionary.ToArray()[0]);

        }

    }

    public class Model

    {

        public string FirstName {get; set; }

        public string LastName { get; set; }

    }

}