I'm using an unbound multi select list box in an Access 2010 accdb.
I want to apply a filter to the form so that it displays data for the
currently selected row in the list box when I move from row to row in the
list box using the down arrow key.
(Note: I can do the same thing without a problem using the After Update
event for the list box when a row is selected using the mouse, but I also
want to provide the ability to use the keyboard only.)

But when the arrow down keyboard key is used, the after update event doesn't
trigger until after the focus moves to the next row, so that the form
displays the data for the previously selected row.

I've tried using the following in the KeyDown event for the list box:
If KeyCode = vbKeyDown Or KeyCode = vbKeyUp Then
MsgBox Me!lstLAN
End If
Before the event triggers, the list box has a non null value, and the arrow
down does move to the next row. But the code generates a null value even
though the focus has moved to the next row.

I really don't understand why the afterupdate behaviour should be different
for mouse clicking vs arrow down, but I would like to be enlightened.
Does anyone have an alternative solution for what I'm trying to achieve.

Bob Darlington
Brisbane

"Bob Darlington" <bob (AT) notheredpcman (DOT) com.au> wrote

A listbox's click event fires for each up or down navigation, so use that
instead of afterupdate. HTH

"Stuart McCall" <smccall (AT) myunrealbox (DOT) com> wrote


Thanks Stuart, but the Click event still still returns a null value - the
same as KeyDown.
--
Bob Darlington
Brisbane

You sure about "Before the event triggers, the list box has a non null
value"?

At least in previous versions of Access, a multi-select list box always
returns a Null value, even if only a single item is selected. The only way
to address its values was through its ItemsSelected collection.


"Bob Darlington" wrote in message
news:4e2769c5$0$22474$afc38c87 (AT) news (DOT) optusnet.com.au...

I'm using an unbound multi select list box in an Access 2010 accdb.
I want to apply a filter to the form so that it displays data for the
currently selected row in the list box when I move from row to row in the
list box using the down arrow key.
(Note: I can do the same thing without a problem using the After Update
event for the list box when a row is selected using the mouse, but I also
want to provide the ability to use the keyboard only.)

But when the arrow down keyboard key is used, the after update event doesn't
trigger until after the focus moves to the next row, so that the form
displays the data for the previously selected row.

I've tried using the following in the KeyDown event for the list box:
If KeyCode = vbKeyDown Or KeyCode = vbKeyUp Then
MsgBox Me!lstLAN
End If
Before the event triggers, the list box has a non null value, and the arrow
down does move to the next row. But the code generates a null value even
though the focus has moved to the next row.

I really don't understand why the afterupdate behaviour should be different
for mouse clicking vs arrow down, but I would like to be enlightened.
Does anyone have an alternative solution for what I'm trying to achieve.

Bob Darlington
Brisbane

Thanks Douglas,
I should have said 'when' not 'before'. The null occurs at the MsgBox line
in the code snip I posted.
I wasn't aware of the null value being returned by a multi select list box
even with a single item is selected, so thanks for the info. I still don't
understand why though.
At any rate, I think I've got a way around my problem, which I'll post here
later, if it tests OK.

--
Bob Darlington
Brisbane
"Douglas J Steele" <NOSPAM_djsteele (AT) NOSPAM_gmail (DOT) com> wrote

"Bob Darlington" <bob (AT) notheredpcman (DOT) com.au> wrote

I've come up with a solution (albeit a bit clunky) to my problem which
others might be interested in.

'Set module level variables:
Dim mIndex as Integer, mblnKeyDown as boolean

'In the list box KeyDown event:
If KeyCode = vbKeyUp Or KeyCode = vbKeyDown Then
mblnKeyDown = True
If KeyCode = vbKeyDown Then mIndex = Me!MyListBox.ListIndex + 1 Else
mIndex = Me!MyListBox.ListIndex - 1
End If

'Then, in the list box AfterUpdate event:
If mblnKeyDown Then
DoCmd.ApplyFilter , "LAN = " & Me!MyListBox.ItemData(mIndex)
mblnKeyDown = False
End If

--
Bob Darlington
Brisbane

"Bob Darlington" <bob (AT) notheredpcman (DOT) com.au> wrote in
news:4e28a95a$0$2444$afc38c87 (AT) news (DOT) optusnet.com.au:

A multiselect listbox has no value because its selection is a
collection. How could it possibly have a value in that case?

--
David W. Fenton http://www.dfenton.com/
contact via website only http://www.dfenton.com/DFA/