public virtual void OnSpeedChanged(int oldSpeed, int newSpeed)
{
SpeedChangedEventArgs e = new SpeedChangedEventArgs();
e.OldSpeed = oldSpeed;
e.NewSpeed = newSpeed;
if (_speedChangedEventHandler != null)
{
_speedChangedEventHandler(this, e);
}
}
static void CarSpeedChanged(object source, SpeedChangedEventArgs e)
{
Console.WriteLine("Car speed changed from {0} to {1}",
e.OldSpeed, e.NewSpeed);
}