Program.cs

using System;

namespace FacadePattern
{
class Computer
{
  public void GetElectricShock()
  {
    Console.Write("Ouch!");
  }

  public void MakeSound()
  {
    Console.Write("Beep beep!");
  }

  public void ShowLoadingScreen()
  {
    Console.Write("Loading..");
  }

  public void Bam()
  {
    Console.Write("Ready to be used!");
  }

  public void CloseEverything()
  {
    Console.Write("Bup bup bup buzzzz!");
  }

  public void Sooth()
  {
    Console.Write("Zzzzz");
  }

  public void PullCurrent()
  {
    Console.Write("Haaah!");
  }
}

class ComputerFacade
{
  private readonly Computer mComputer;

  public ComputerFacade(Computer computer)
  {
    this.mComputer = computer ?? throw new ArgumentNullException("computer", "computer cannot be null");
  }

  public void TurnOn()
  {
    mComputer.GetElectricShock();
    mComputer.MakeSound();
    mComputer.ShowLoadingScreen();
    mComputer.Bam();
  }

  public void TurnOff()
  {
    mComputer.CloseEverything();
    mComputer.PullCurrent();
    mComputer.Sooth();
  }
}
  class Program
  {
    static void Main(string[] args)
    {
      var computer = new ComputerFacade(new Computer());
      computer.TurnOn(); // Ouch! Beep beep! Loading.. Ready to be used!
      Console.WriteLine();
      computer.TurnOff();  // Bup bup buzzz! Haah! Zzzzz
      Console.ReadLine();
    }
  }
}