gridView otomatik biçimlendirme

for (int i = 0; i < gridView6.Columns.Count; i++)
{
string tipi = this.gridView6.Columns[i].ColumnType.ToString();  
          if (tipi == "System.Double" || tipi == "System.Decimal")
            {
                gridView6.Columns[i].DisplayFormat.FormatType = FormatType.Numeric;
                gridView6.Columns[i].DisplayFormat.FormatString = "n2";
                gridView6.Columns[i].SummaryItem.SummaryType = DevExpress.Data.SummaryItemType.Sum;
                gridView6.Columns[i].SummaryItem.DisplayFormat = "{0:N2}";
                gridView6.Columns[i].SummaryItem.Tag = 1;
            }

            if (tipi == "System.DateTime")
            {
                gridView6.Columns[i].DisplayFormat.FormatType = FormatType.DateTime;
                gridView6.Columns[i].DisplayFormat.FormatString = "dd.MM.yyyy";
            }
        }