Hi Mick,
Thanks again for responding.
OnValidate? I'll give that a go. I am interested in being
able to substitute a different object for the one being
added - in other words I want to replace the object
created by the Editor with a same-type object of my own
creation, with various settings of its data members. I'm
hoping I can do something like simply replace the object
reference of the passed-in argument with the new one.
Anyway, I'll try.. thanks!
PS ...you'd think they might make this gizmo a little more
developer-friendly! Wherever there is user input,
developers are going to want to control the process --
this CollectionEditor does all of this in avery non-
intuitive way (why, for example, can't OnInsert, instead
of returning 'void', return a bool that cancels the
operation if false?). If it would simply call the
appropriate methods in the collection class (Remove, Add,
etc.) instead of all this behind-the-scenes monkeying
about, life would be much simpler...
MP
-----Original Message-----
You can stop the user adding an object to the collection
by throwing anException/ArgumentException in the OnValidate methods of
the CollectionBaseclass. This will force the user to either correct the
Object or remove it.
You can use the CollectionEditor's CanRemoveInstance()
Method to stop theuser removing an object.
"m. pollack" <an*******@discussions.microsoft.com> wrote
in messagenews:0d****************************@phx.gbl... Hi all,
I have subclassed the CollectionEditor object in order
to override its OnInsert and OnRemove methods (because I am
exposing some properties (including a collection
property) of a class object at runtime with a PropertyGrid, and
needed to know when the user was adding objects to, or
removing objects from, the collection. My question is:
Can I use the OnInsert method to block the user from
modifying collection if the object to be added/removed fails some
test? OnInsert and OnRemove just return "void", so I
don't see how, but the docs suggest that it can be done.
One complication of using the CollectionEditor is that
it seems not to add/remove objects by calling the
collection class's Add or Remove methods (removal, for instance,
seems to just happen somehow via
(CollectionEditor.DestroyInstance()), but rather by
grabbing the whole inner list, working with
it "offline", and then just plunking it back in.
Any ideas?
.
