Question

Say I have a function that does the following in Vb.net

For i as decimal = 0 to mstrItems.count - 1
  mstrItems.item(i).activate
next

And I have classes as such that both classes, though different object type, have the function activate.

I would like to iterate my Items as above, having the list include any type of object, not just one specific type, and have the different objects all perform the activate function in the same way, though they are different object types.

Cheers!
Martin

Answer 1

Alternatively, you could define an interface and implement it in all your different Types:

Interface IActivateable
  Sub Activate
End Interface

Class MyType1: Implements IActivateable
Sub Activate Implements IActivateable.Activate
'some implementation details here ...
End Sub
End Class

Class MyType2: Implements IActivateable
Sub Activate Implements IActivateable.Activate
'some implementation details here ...
End Sub
End Class

Then you can cast each type as the interface you want to handle:

 Dim myList as new list(of IActivateable)
 myList.add(new MyType1)
 myList.add(new MyType2)

 for each obj as IActivateable in myList
     obj.Activate
 end for