using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        // Controller for instance  

        // this works well

        Customer custom = new Customer(1, "titi");

        Console.WriteLine(custom.Name);         // titi

        Console.WriteLine("App continues");

        Console.WriteLine(custom.BigObject);    //toto but Gettor called before getting toto

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

        // test

        CustomerUI ui = new Customer(2, "tata").ToCustomerUI();

        Console.WriteLine(ui.Name);         // titi

        Console.WriteLine("App continues");

        Console.WriteLine(ui.BigObject);

        // test 2

    }

    // BL layer

    public static Customer BL_GetUser()

    {

        return new Customer(1, "toto");

    }

}

​

​

public class Customer

{

    public int CustomerID { get; set; }

    public string Name { get; set; }

    // private store public handle

    private Lazy<string> _BigObject = null;

    public string BigObject

    {

        get

        {

            return _BigObject.Value;

        }

    }

    // ctor

    public Customer(int id, string name)

    {

        CustomerID = id;

        Name = name;

        // Lazy Load

        _BigObject = new Lazy<string>(() => DAL_LoadBigObject() );

    }

    // mapping

    public CustomerUI ToCustomerUI()

    {

        CustomerUI ui = new CustomerUI();

        ui.CustomerID = this.CustomerID;

        ui.Name = this.Name;

        // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! dirty

        ui.SetLazy( new Lazy<string>(() => this.BigObject ) );

        return ui;

    }

    public string DAL_LoadBigObject(){

        Console.WriteLine("CALL API");

        return "Toto";

    }

​

} 

​

// UI object / VM

public class CustomerUI

{

    // copy paste of entity

    public int CustomerID { get; set; }

    public string Name { get; set; }

    private Lazy<string> _BigObject = null;

    public string BigObject

    {

        get

        {

            return _BigObject.Value;

        }

    }

    public void SetLazy(Lazy<string> myLazyString){

        _BigObject = myLazyString;

    }

}