OnClientDropping
The OnClientDropping client-event occurs before the items are dropped. The event can be cancelled.
The event handler receives two parameters:
The instance of the listbox firing the event
An event arguments parameter containing the following methods:
get_sourceItem() - returns the first selected item that is dropped
get_sourceItems() - returns an array of the selected items that are dropped
get_destinationItem() - returns the destination item.
get_dropPosition() - returns the relative position either 0 (Above) or 1 (Below) toward the destination item.
get_htmlElement() - returns the DOM html element which the item is dropped onto.
set_cancel() - lets you cancel the event and prevent the dropping.
get_domEvent() - returns the DOM event object
The following example shows how to ask the user for confirmation before the item is dropped.
function OnClientDroppingHandler(sender, eventArgs) {
var message = "Are you sure you want to drop the item " + eventArgs.get_sourceItem().get_text();
message += eventArgs.get_dropPosition() == 0 ? " above" : " below";
message += " the item " + eventArgs.get_destinationItem().get_text() + "?";
if (!confirm(message))
eventArgs.set_cancel(true);
}