Optional column headers are available for single- and multi-column trees. Column headers consist of one or multiple rows of cells. Individual cells within the column headers can be accessed using the HeadersClass.Item property. Languages supporting indexers can use array syntax, usually Headers or Headers().
Cells within column headers offer all the cell properties and can contain zero, one or several parts, such as text, images, buttons, checkboxes, radiobuttons, progressbars, and more. The HeadersClass.SortIndicatorPositionDefault property is used to define the position of optional sort indicators. The actual display of the sorting indicator is defined individually for each cell using the cell's CellBaseClass.SortStatus property. By using cell merging within column headers, cells can be merged vertically and/or horizontally.
If a user clicks on a column header, the ItemClick event or ItemDoubleClick event occurs. In addition to the ItemClick event, the properties HeadersClass.LastClicked, HeadersClass.ClickedRow and HeadersClass.ClickedColumn are useful to determine the header clicked.