On Mar 26, 2006, at 5:50 PM, Charles Yeomans wrote:
On Mar 26, 2006, at 5:20 PM, William Squires wrote:
Given an array of type <reference-to-baseclass> (whatever 'baseclass'
happens to be), and some instances of the base class (and subclasses
thereof) stored in an array, fMyArray; when I step through the array
like so:
Dim i As Integer
Dim l As Integer
Dim theItem As BaseClass
Dim theSubclassItem As Subclass
If (fNumItems > 0) Then
l = fNumItems - 1
For i = 0 To l
theItem = fMyArray(i)
If (theItem IsA Subclass) Then
// Shouldn't this work?
theSubclassItem = Subclass(theItem)
theSubclassItem.DoSubclassThing()
Else
// tests for other subclasses...
End If
Next
End If
shouldn't IsA tell me if the instance referred to by 'theItem' (after
the assignment from the array) is really an instance of BaseClass or
Subclass, even though the compile-time type of 'theItem' is
'BaseClass' (and ditto for the array, since otherwise you wouldn't be
able to store base class instances in it if you DIMmed it as a
compile-time type of one of BaseClass' subclasses.)? i.e. shouldn't
IsA work polymorphicly?
Yes, the code above should work as you expect.
But apparently doesn't in RB 5.2.4 (Win) and compiled to Windows
(WinXP box). See the previous message thread, "IsA isn't."
--------------
Charles Yeomans
_______________________________________________
Unsubscribe or switch delivery mode:
<http://www.realsoftware.com/support/listmanager/>
Search the archives of this list here:
<http://support.realsoftware.com/listarchives/lists.html>
William H Squires Jr
4400 Horizon Hill #4006
San Antonio, TX 78229
[EMAIL PROTECTED] <- remove the .nospam
_______________________________________________
Unsubscribe or switch delivery mode:
<http://www.realsoftware.com/support/listmanager/>
Search the archives of this list here:
<http://support.realsoftware.com/listarchives/lists.html>
