Ordering Example

    public partial class Form1 : Form
    {
        private static Random random = new Random();

        private string[] ItemNames =  { "Leather", "Shield", "Apple", "Sword"};

        private List<GameItem> Items = new List<GameItem>();

        public Form1()
        {
            InitializeComponent();
        }

        private void addButton_Click(object sender, EventArgs e)
        {
            //Create a dummy game item
            var gameItem = new GameItem();
            gameItem.Name = ItemNames[random.Next(0, ItemNames.Length)]; //Random name
            gameItem.Quantity = random.Next(1, 15); //Random quantity

            Items.Add(gameItem); //Add to collection

            //Create an rodered collection
            var orderedList = Items.OrderByDescending(x => x.Quantity).ToList();

            //Clear current listbox
            inventoryListbox.Items.Clear();

            //Add ordered items
            foreach(var item in orderedList)
            {
                inventoryListbox.Items.Add(item.Name + " : " + item.Quantity);
            }
        }
    }

    //Item container object
    public class GameItem
    {
        public string Name { get; set; }
        public int Quantity { get; set; }
    }