Polymorphism

[morjaria]

I have two classes called A and B. They both use a sub procedure within them called calculate_V2. Each class calculates V2 differently.
From my form I want to call one of these sub procedures depending on the situation. So I created an interface to link the two classes called class_interface. In class A and B I wrote 'Implements class_interface' at the top.

In the interface class I wrote
Public Sub calculate_V2()
End Sub

In class A and B I wrote
Public Sub class_interface_calculate_V2()
'calculating code
End Sub

Then in the form, I created a class A object, a class B object and class_interface object. I make class_interface equal class A or B depending on the situation. So when I have 'class_interface.calculate_V2' it calls the associated sub procedure.
Example:
Set class_interface = class A
class_interface.calculate_V2
'This calls calculate_V2 from class A

Set class_interface = class B
class_interface.calculate_V2
'This calls calculate_V2 from class B

This all works fine, sorry for blabbing on!

The problem is class A and B both have the property V2
I want to retrieve this property from either class by using the class_interface.
So in class_interface

Public Property Get V2() as Double
End Sub

In Class A and B
Public Property Get class_interface_V2() as Double
class_interface_V2 = mvarV2
End Sub

So now I want to be able to do this:
Set class_interface = class A
variable = class_interface.V2
'Get the V2 property from class A

Set class_interface = class B
variable = class_interface.V2
'Get the V2 property from class B

But when I run the project I get this error:
Object module needs to implement 'class_interface_V2' for 'class_interface'.
But I think I have already done this!

[billrogers]

I may be mistaken but I do not believe polymorphism and inheritance, which is what your are attempting to do, can not be done yet in vb.

It will be available in visual basic 7 which is scheduled to release first quarter 2001.

Check on microsoft's site, and some other developers and you will find articles talking of how vb 7 will include inheritance...