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