public void OnPriceChange(PriceChangedEventAgrs e)
{
PriceChanged?.Invoke(this, e);
//if (PriceChanged != null)
//{
// PriceChanged(this, e);
//}
}
public static void product_PricecChanged(object sender, PriceChangedEventAgrs e)
{
Console.WriteLine("Old price: " + e.OldPrice);
Console.WriteLine("New price: " + e.NewPrice);
}