When the value of this property is set to a string value, the ListBox searches for the item within the ListBox that matches the specified text and selects the item. You can also use this property to determine which items are currently selected in the ListBox. If the SelectionMode property of the ListBox is set to SelectionMode.MultiExtended, this property returns the text of the first selected item. If the SelectionMode property of the ListBox is not set to SelectionMode.None, this property returns the text of the first selected item.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)