All columns whose SortDirection property has been set to Ascending or Descending are automatically added to the grid's collection or sorted columns. If a column's SortDirection property is set to None, the column will automatically be removed from the collection.
Requirements
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2