OnClientItemsRequested
The OnClientItemsRequested client-side event occurs after the load-on-demand mechanism has added new items to the listbox.
The event handler receives the following parameter:
- The instance of the listbox firing the event.
<script type="text/javascript">
function OnClientItemsRequested(sender, eventArgs) {
alert("There are " + sender.get_items().get_count() + " items.");
}
</script>