Composite

//    Full Tutorial on indiedevart.wordpress.com


using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication108
{
    public interface IInventory
    {
        string Name { get; set; }
        void PrintName();
    }

    public class Backpack : IInventory, IEnumerable<IInventory>
    {
        private List<IInventory> _subordinates = new List<IInventory>();

        public string Name { get; set; }

        public void AddSubordinate(IInventory subordinate)
        {
            _subordinates.Add(subordinate);
        }

        public void RemoveSubordinate(IInventory subordinate)
        {
            _subordinates.Remove(subordinate);
        }

        public IInventory GetSubordinate(int index)
        {
            return _subordinates[index];
        }

        public void PrintName()
        {
            Console.WriteLine(Name);
        }
        public IEnumerator<IInventory> GetEnumerator()
        {
            foreach (IInventory subordinate in _subordinates)
            {
                yield return subordinate;
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    public class Item : IInventory
    {
        public string Name { get; set; }

        public void PrintName()
        {
            Console.WriteLine(Name);
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Backpack inventory= new Backpack{  Name = "Inventory" };
            Backpack backpack = new Backpack { Name = "Backpack" };

            inventory.AddSubordinate(backpack);
            inventory.AddSubordinate(new Item { Name = "Sword" });
            inventory.AddSubordinate(new Item { Name = "Armor" });

            backpack.AddSubordinate(new Item { Name = "Shield" });

            Console.WriteLine("List of items in inventory");
            foreach (IInventory element in inventory)
            {
                element.PrintName();
            }
            Console.ReadKey();
        }
    }
}