Computer Programming Concepts and Visual Basic David I. Schneider

frmCircles.ForeColor = vbRed ‘Make future circles red
End If
End Sub
Private Sub cmdQuit_Click()
End
End Sub
[Run and press the “Move and Show Circle” button seven times. Note: The last circle will be colored
red.]
COMMENTS
1. Perhaps a better name for “user-defined events.” would be “programmerdefined
events.”
2. A statement of the form
collectionName.Add objectName, keyString
can also be written as
collectionName.Add Item:=objectName, Key:=keyString
3. The WithEvents keyword cannot be inserted into a declaration statement of the
form
Private objectName As Object
It can only be used when a specific class follows the word “As.”
4. Collections require more memory than arrays and slow down execution time. If
either a collection or an array would suffice, choose an array. This will often be
the case when the number of items is fixed. For instance, a deck of cards should
be represented as an array of card objects rather than a collection of card
objects.
12.3 CLASS RELATIONSHIPS
Collections and Events 373
The three relationships between classes are “use,” “containment,” and “inheritance.” One class
uses another class if it manipulates objects of that class. We say that class A contains class B