After PaymentCreatedEventHandler state mistakes should be how to deal with?

[zhangzw218]

if (order.PaymentId.HasValue || order.OrderStatus != OrderStatus.Pending)
{
    // Todo: should cancel the payment?
    throw new OrderIsInWrongStageException(order.Id);
}

In a certain scenario, order.orderstatus = Canceled, the order has been canceled and the payment has been canceled.
Then the payment transaction side is still subscribed to the event, triggering this progress exception issue.
How do I discard this event? Is to make sure that this mistake never happens again?

[gdlcf88]

As the todo said, this process flow should be improved.