Hi gang,

I have a silly question... silly in that I have been an OO developer for almost 19 years now, and this issue just hit me in VB.NET, and I am not sure if my thinking is correct for the language.

I have an abstract class DataBroker, and I want to force all derived classes to implement some specific functionality. One of those methods is Delete.

Now in the DataBroker abstract class, I write the method template:
BO is an object that will be passed as an example of what to delete.

In my subclass, PersonDataBroker, I override the function:
Note that Person IS a subclass of BO.

This causes an error saying that I have not overridden the method, assumedly because the passed types differ.

So, here is the deal... I want to force subclasses to implement this method, but the subs will know what specific BO type they are getting. I need to be able to call functionality on the specific BO type (i.e. Person) in the specialized data broker (i.e. PersonDataBroker).

With me so far?

So, it seems to be that I need to OverLOAD the abstract function... but for some reason that just feels wrong.

Am I missing something here or is this the way to do it?

I was going to use Generics, but that does not seem to fit the bill properly either.

Any help greatly appreciated!

Chris

So you cannot use As BO in the overriding declaration and pass it a Person? Does that violate your needs? Does that compile?

Hi Brian,

I think I did end up using the generic, but I had to discover constraints (especially the New constraint) before it worked.

The solution ended up looking something like:
No more need to override in subclasses, just pass the type per usual in the function call.

Thanks!

Chris