public void AddItem(Guitar guitar, int quantity) { CartLine line = lineCollection .Where(p => p.Guitar.Id == guitar.Id) .FirstOrDefault(); if (line == null) { lineCollection.Add(new CartLine { Guitar = guitar, Quantity = quantity }); } else { line.Quantity += quantity; } }
public void RemoveLine(Guitar guitar) { lineCollection.RemoveAll(l => l.Guitar.Id == guitar.Id); }