property Group.ExpandOnDblClick as Boolean
Specifies whether the item is expanded or collapsed if the user dbl clicks the item.

TypeDescription
Boolean A boolean expression that indicates whether an item is expanded on dbl click. 

Use the ExpandOnDblClick property to disable expanding or collapsing items when user dbl clicks an item. By default, the ExpandOnDblClick property is True. Use the ExpandOnKeys property to specify whether the control expands or collapses a node when user presses arrow keys. 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.