I know VB6 is known for having poor OOP support but basic polymorphism appears to work (at least for Subs, Functions and Properties), however my problem is that I can't work out how to raise events from the inherited classes.

I have 3 classes - clsBase, clsInheritedA, clsInheritedB.

In clsBase I have:
etc.

And I want to raise the TestEvent event from clsInheritedA:
etc.

But it gives me "Event not found" on the "RaiseEvent TestEvent" line when I try to compile it.

Does anyone know what I am missing to let the inherited class raise the events of the base class so that the host application can then respond to those events (i.e. TestEvent) when it has done:

Then later:


Thanks in advance for any help.

This post has been edited by adw888: 26 Jul, 2008 - 09:34 AM

I'm not sure if this is even supported. It seems like I've run into this issue as well, and solved it by using a helper class. Unfortunately, it requires more work than the obvious way that should have been supported.

I can say that firing events from implemented classes is definitely not supported. The oop support isn't so much "poor" as it is "old technology".

Agreeing with perfectly.insane (lol... that's some member name, eh? :-) that you'll need a helper class.

I have a sample on my site that shows how to get events from controls that are dynamically loaded, but not part of a control array... or even get the same event from multiple types of controls (something a lot of dotNetters think VB6 is incapable of)

Add Controls at Runtime With Events (kind of)
http://www.vbsight.com/CodeA.htm#AddControls2

It's not an extensive sample, but shows the basics and contains a lot of comments... as with every sample on my site, it was written to answer a question in a newsgroup somewhere.

If that sample doesn't help, there are many others floating around the web. My "links" page contains links to some of the most advanced VB6 programmers and samples on earth, so.... take a peek.

After re-reading, I thought I'd add...

Intellisense in VB6 is the best there is (imo)

If you type RaiseEvent(space) and your event doesn't show in intellisense, it won't work. Period. Same goes with WithEvents. If the class you need events from doesn't show after typing WithEvents(space), you won't be able to get events from that class.

In fact, while typing code, you'll find that every single variable, class, property, anything else you can think of, that's currently available to that specific procedure, will show in intellisense.

...and, if intellisense isn't showing at all, that means there's a syntax error somewhere or a missing library and the program won't compile at all... the good news there is, if you attempt to compile, since the VB6 compiler stops as soon as it can't resolve something, the line of code causing the problem will be shown in the code window and highlighted.

There is a "gotcha" there too. Some keywords (the list is very, very short) that are built deeply into the runtime won't show for some crazy reason (forgot the specifics). For example, if you type Printer(dot) you'd assume "Print" to be in the list of available properties and methods... it's not.

Thanks for your replies perfectly.insane and Ken Halter.
Your site looks particularly useful Ken, so a further thanks for the link.

It's a shame that MS didn't do a "VB7" with the classic VB6 syntax but newer OOP support and other bugfixes; that would have been much superior to VB.NET in my opinion.