[DUG] ListView - Scroll Event

Robo robo555 at gmail.com
Mon Jul 28 06:57:40 NZST 2014


So you just need to use the OnChange event, and check the item is not nil.
>From memory I don't think you need to check whether item is different to
previous item.

Robo


On Sun, Jul 27, 2014 at 8:52 PM, Eric A <eaa603 at hotmail.com> wrote:

> Yes, multiple OnChange events are generated on the ListView control, for
> both mouse clicks and navigation key depressions, as follows:
>
> a) First mouse click or down arrow/PgDn key depression:
> - Item = new selection
>
> b) subsequent mouse clicks or down arrow/PgDn key depressions:
> - Item - current selection
> - Item= nil
> - Item = new selection
>
> Seems messy ...
>
> ------------------------------
> From: robo555 at gmail.com
> Date: Sun, 27 Jul 2014 12:28:33 +0200
> To: delphi at listserver.123.net.nz
>
> Subject: Re: [DUG] ListView - Scroll Event
>
> From memory, when a record changes, first an event gets fired where
> selected item is nil, then a second event gets fire where selected item is
> the new item.
>
>
> On Sun, Jul 27, 2014 at 11:07 AM, Eric A <eaa603 at hotmail.com> wrote:
>
> (Delphi 7)
>
> I  wish to detect the user selecting a row (item) in a ListView component
> to display child records for  the item in another control.
>
> There is no "OnScroll" event for this control.  I can use the "OnClick"
> event OK for a selection cia the mouse, but how do I detect when a user
> scrolls on to a record by using the arrow keys (or PgUp, PgDn or moving the
> scrollbar ?
>
> I have tried the using the OnChange event but it seems that there are two
> events generated for each movement by the arrow keys.
>
> Does anyone have a code snippet to accomplish this?
>
> Eric.
>
> _______________________________________________
> NZ Borland Developers Group - Delphi mailing list
> Post: delphi at listserver.123.net.nz
> Admin: http://delphi.org.nz/mailman/listinfo/delphi
> Unsubscribe: send an email to delphi-request at listserver.123.net.nz with
> Subject: unsubscribe
>
>
>
> _______________________________________________ NZ Borland Developers
> Group - Delphi mailing list Post: delphi at listserver.123.net.nz Admin:
> http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email
> to delphi-request at listserver.123.net.nz with Subject: unsubscribe
>
> _______________________________________________
> NZ Borland Developers Group - Delphi mailing list
> Post: delphi at listserver.123.net.nz
> Admin: http://delphi.org.nz/mailman/listinfo/delphi
> Unsubscribe: send an email to delphi-request at listserver.123.net.nz with
> Subject: unsubscribe
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://listserver.123.net.nz/pipermail/delphi/attachments/20140727/5b3670ee/attachment.html 


More information about the Delphi mailing list