property ExplorerTree.ExpandOnClick as Boolean
Expands the group when its caption is clicked.

TypeDescription
Boolean A boolean expression that indicates whether the control expands or collapses the group when the group's caption is clicked. 

Use the ExpandOnClick property to specify whether the control expands or collapses when the user clicks the group's caption. Use the ExpandIcon property to assign new expanded/collapsed icons for the groups.