property Column.DefaultSortOrder as Boolean
Specifies whether the default sort order is ascending or descending.

TypeDescription
Boolean A boolean expression that indicates the default sort order. 

Use the DefaultSortOrder property to specify the default sort order, when the column's header is clicked. Use the SortOnClick property to specify when user can sort the columns by clicking the control's header. The SortOrder property specifies the column's sort order. Use the SortChildren method to sort  items at runtime.