xlWorkSheet.get_Range("A1", "D1").Font.Bold = true;
xlWorkSheet.get_Range("A1", "D1").Font.Color = Color.Blue;
xlWorkSheet.get_Range("A1", "D1").Borders.Color = Color.Violet;
xlWorkSheet.get_Range("A1", "D1").Borders.LineStyle = XlLineStyle.xlContinuous;
xlWorkSheet.get_Range("A1", "D1").Borders.Weight = Microsoft.Office.Interop.Excel.XlBorderWeight.xlMedium;