OnClientItemChecking

The OnClientItemChecking client-side event occurs when the user selects a checkbox using mouse or keyboard. The checked state returned by the item's get_checked() function has not changed to reflect the new value. The event can be cancelled.

The event handler receives two parameters:

1. The instance of the listbox firing the event

2. An event arguments parameter containing the following methods:

• get_item() - returns the checked item

• set_cancel() - lets you cancel the event and prevent changing the checked state of the item.

• get_domEvent() - returns the DOM event object

The example below shows how to check an item after the user clicks OK in the confirmation dialog:

JavaScript

function OnClientItemCheckingHandler(sender, eventArgs) {
	var item = eventArgs.get_item();
	var message = "Are you sure you want to ";
	message += item.get_checked() ? "uncheck" : "check";
	message += " the item " + item.get_text();
	if (!confirm(message))
		eventArgs.set_cancel(true);
} 				

See Also

• OnClientItemChecked