using NPOI; using NPOI.XSSF.UserModel; using NPOI.SS.UserModel; using NPOI.HSSF.UserModel; NPOI.SS.UserModel.IWorkbook excelbook = null; using (FileStream fs = new FileStream(Path, FileMode.OpenOrCreate, FileAccess.ReadWrite)) { if (fix == ".xls") { excelbook = new HSSFWorkbook(fs); } else if (fix == ".xlsx") { excelbook = new XSSFWorkbook(fs); } ISheet sheet = excelbook.GetSheetAt(0); for (int i = 1; i < sheet.LastRowNum; i++) { IRow row = sheet.GetRow(i); foreach (var item in row.Cells) { item.SetCellType(CellType.String); } var data = row.Cells[0].StringCellValue; var data2 = row.Cells[1].StringCellValue; } }