When receiving subclass events, the VB collection class should assign values to the Collection class.

Generally, the following method is used to assign values to the Collection class. However, this method only applies to the collectoin object and does not trigger the event of the subclass.
For I = 1 to ncount
Ocols (I). property1 = ABC
Next
So the value assignment in the Set class should be changed
Dim aobj as csubclass1
For I = 1 to ncount
Set aobj = ocols (I)
Aobj. property1 = ABC
Next
In this way, all events in the subclass can be triggered.
The premise is that when defining a collection class, you need to define the subclass as a class variable, such:
Dim withevents objnewmember as csitem
Events that receive subclass must be defined
Sub objnewmember _ event name (param1 ...)
End sub
Below...
Public Function add (PO as string ,...)
End Function
...