protected virtual void OnPriceChanged(PriceChangedEventArgs e)
{
if (PriceChanged != null)
{
PriceChanged(this, e);
}
}
private static void Iphone_PriceChanged(object sender, PriceChangedEventArgs e)
{
Console.WriteLine("IPhone price from {0} to {1}", e.OldPrice, e.NewPrice);
}