🚀 go-pugleaf

"Jim Levett" <jim.levett@kaleidovision.co.uk> wrote in message 
news:48847edc$1@newsgroups.borland.com...

> 1; When selecting a number of items using a click for the first item, and 
> then holding shift and clicking on the last desired item, the onselectitem 
> event is not called at all after the first click, therefore missing out a 
> whole list of selected items and deselected items.

It is not supposed to.  The OnSelectItem event is fired in reply to the 
LVN_ITEMCHANGED message, which is not sent for item ranges in an owner-data 
ListView.  This is clearly documented by Microsoft:

    LVN_ITEMCHANGED Notification
    http://msdn.microsoft.com/en-us/library/bb774845.aspx

    "If a list-view control has the LVS_OWNERDATA style, and the user 
selects a range of items by holding down the SHIFT key and clicking the 
mouse, LVN_ITEMCHANGED notifications are not sent for each selected or 
deselected item. Instead, you will receive a single LVN_ODSTATECHANGED 
notification, indicating that a range of items has changed state."

The LVN_ODSTATECHANGED fires the TListView's OnDataStateChange event.  You 
will have to use that event to handle ranges.
> Currently, instead of just adding/removing the data for the respective 
> selected/deselected items as the selection event is called, I`m having to 
> go through the entire list using getnextitem and reconstructing the 
> stringlist of data each time. This seems like quite an overhead with 
> 16000+ items (this grows monthly by 200 or so entries)

Calling TListView.GetNextItem() triggers the OnData event for each matching 
item because it returns a TListItem pointer, so the TListItem properties 
have to be filled in.  If your OnData event handler takes some time to look 
up the item data, that will slow down the loop considerably.  If you are 
only interested in finding index numbers instead, then I suggest you use the 
ListView_GetNextItem() macro directly instead.  I find that working with API 
messages directly can considerably improve performance when working with 
owner-data ListViews.  In this case, you could use ListView_GetNextItem() to 
find the selected indexes, and then use those indexes to access your data 
storage directly without going through the ListView at all.



Gambit