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model.CellModels.Add("ColumnHeaderCell", new GridSortColumnHeaderCellModel(model));
To handle drawing s special sort header, you can derive a custom cell control and handle it that way. Or, you could try catching the CellDrawn event, and if the cell being drawn is a ColumnHeaderCell, then draw the extra character over what is drawn by default. This sendond alternative does not require creating your own cell control.