onExpand
Event fired after a checkbox in a tree item is clicked.
Parameters
<oItem>
The TreeItem whose + or - has been clicked.
Property of
TreeView
Description
The onExpand event fires after the user has expanded or collapsed a tree item’s subtree through the user interface, usually by clicking the + or - icon. Check the expanded property of the tree’s currently selected tree item to see whether the subtree is now expanded or not.