property G2antt.AllowSelectNothing as Boolean
Specifies whether the current selection is erased, once the user clicks outside of the items section.

 TypeDescription 
   Boolean A Boolean expression that specifies whether the current selection is erased, once the user clicks outside of the items section.  
By default, the AllowSelectNothing property is False. The AllowSelectNothing property specifies whether the current selection is erased, once the user clicks outside of the items section. For instance, if the control's SingleSel property is True, and AllowSelectNothing property is True, you can un-select the single-selected item if pressing the CTRL + Space, or by CTRL + click.