workbook.Save("Report.xlsx"); For truly massive files (500k+ rows), use the LoadOptions to stream data:
var workbook = new ExcelFile(); var worksheet = workbook.Worksheets.Add("Sales Report"); gembox.spreadsheet.dll
worksheet.Cells[1, 0].Value = "Widget"; worksheet.Cells[1, 1].Value = 10; worksheet.Cells[1, 2].Value = 5.99; worksheet.Cells[1, 3].SetFormula("=B2*C2"); workbook
// Add data worksheet.Cells[0, 0].Value = "Product"; worksheet.Cells[0, 1].Value = "Qty"; worksheet.Cells[0, 2].Value = "Price"; worksheet.Cells[0, 3].Value = "Total"; For truly massive files (500k+ rows)