public void RemoveItem(Product product) { ProductLine line = lineCollection.Where(p => p.Products.First().ProductID == product.ProductID).FirstOrDefault(); line.Products.RemoveLast(); if (line.Quantity <= 0) { lineCollection.Remove(line); } }
public void AddItem(Product product) { ProductLine line = lineCollection.Where(p => p.Products.First().ProductID == product.ProductID).FirstOrDefault(); if (line == null) { lineCollection.Add(new ProductLine(product)); } else { line.Products.AddLast(product); } }