The default behavior of the grid is to not include the CurrentCell in the grid.Selections collection. This is by design.
If you want to include it, one way is to set a couple of excelLike properties.
this.gridControl1.ExcelLikeCurrentCell = true;
this.gridControl1.ExcelLikeSelectionFrame = true;
But you may or may not like the look of this as it draws a fatter selection frame that the default.
If you do not want to use the excel properties, then I think you can handle a couple of events, and manually add/remove the currentcell from teh grid.Selections collection.
private void gridControl1_CurrentCellMoving(object sender, GridCurrentCellMovingEventArgs e)
{
GridCurrentCell cc = this.gridControl1.CurrentCell;
this.gridControl1.Selections.Remove(cc.RangeInfo);
this.gridControl1.Selections.Add(GridRangeInfo.Cell(cc.MoveToRowIndex, cc.MoveToColIndex));
}
private void gridControl1_CellClick(object sender, GridCellClickEventArgs e)
{
this.gridControl1.Selections.Add(GridRangeInfo.Cell(e.RowIndex, e.ColIndex));
}