Use ExpandItem property to programmatically expand or collapse an item. Use the ExpandItem property to check whether an items is expanded or collapsed. To check if the item has child items you can use ChildCount property. Use the ItemHasChildren property to display a +/- expand sign to the item even if it doesn't contain child items. The ExpandOnSearch property specifies whether the control expands nodes when incremental searching is on ( AutoSearch property is different than 0 ) and user types characters when the control has the focus. Use the ExpandOnKeys property to specify whether the user expands or collapses the focused items using arrow keys.