public SaleLineItem GetLineItem(Product product)
{
foreach (var sli in LineItems)
if (sli.Product.Equals(product))
return sli;
return null;
}
public void AddLineItem(Product product, int quantity = 1)
{
SaleLineItem lineItem = GetLineItem(product);
if (lineItem == null)
{
lineItem = new SaleLineItem { Product = product, };
LineItems.Add(lineItem);
}
lineItem.Quantity += quantity;
}
