Aspose.Cells.Workbook book = new Aspose.Cells.Workbook();
Aspose.Cells.Worksheet sheet = book.Worksheets["Sheet1"];
sheet.FreezePanes(1, 1, 1, 0);

Aspose.Cells.Style style = book.Styles[book.Styles.Add()];
style.Pattern = Aspose.Cells.BackgroundType.Solid;

style.Borders.SetStyle(Aspose.Cells.CellBorderType.Thin);
style.Borders.SetColor(System.Drawing.Color.LightSteelBlue);
style.IsTextWrapped = true;
style.Font.Size = 10;

Aspose.Cells.StyleFlag flag = new Aspose.Cells.StyleFlag();
flag.All = true;

sheet.Cells.ApplyStyle(style, flag);

style.VerticalAlignment = Aspose.Cells.TextAlignmentType.Center;
style.Font.IsBold = true;
flag.All = true;

sheet.Cells.Rows[0].ApplyStyle(style, flag);

sheet.Cells.ImportDataTable(dt, true, 0, 0, dt.Rows.Count, dt.Columns.Count, false, "yyyy-MM-dd", false);

book.Save(DateTime.Now.ToString("yyyyMMddhhmmss") + ".xlsx", Aspose.Cells.FileFormatType.Excel2007Xlsx, Aspose.Cells.SaveType.OpenInExcel, Response);