Making My Own Events - Read In Information From A Magnetic Stripe Card

First off, what I'm doing here is trying to read in information from a magnetic stripe card, parse it, validate certain parts and go from there. I'm working on two classes... the first is CardClass and that represents the card itself (well, the data obtained from the card). The class is CardParsingClass. This holds all the card parsing rules.

At one point in the process, I will create an instance of the CardClass. That instance gets passed into the CardParsingClass.ValidateData function:

CODE:

This function steps through each of the card parsing rules and applies the rule to cardCurrent to see if it passes (i.e., is valid).

And here we come to the meat of it.... what I'd like to do is define an event called FailedCardReadEvent. Whenever I raise the FailedCardRead event I could write to the log that it failed, modify variables in the CardClass (particularly the state of the card read variable), etc. So, the way I'm looking to use this would be something like this:

CODE:

So as shown above I'm thinking I should code a FailedCardReadEvent in the CardClass. But I don't know how to do that.

I also don't see how this is different than just calling a subroutine. If I have to manually raise the FailedCardReadEvent isn't that the same as calling a subroutine?

I know I'm missing something but I'm just not getting it. I've spent some time googling this morning and read a few things but I'm just not understanding how it all works.