The RemoveColumn event is invoked when the control is about to remove a column. Use the RemoveColumn event to release any extra data associated to the column. Use the Remove method to remove a specific column from Columns collection. Use the Clear method to clear the columns collection. Use the RemoveItem method to remove an item. Use the RemoveAllItems method to remove all items. Use the CellData property to assign an extra data to a cell. Use the ItemData property to assign an extra data to an item.  Use the Data property to assign an extra data to a column