将单元格格式设置为文本
HSSFWorkbook wk = new HSSFWorkbook();
HSSFSheet sheet = (HSSFSheet)wk.CreateSheet("sheet1");
HSSFRow head = (HSSFRow)sheet.CreateRow(0);
IDataFormat dataformat = wk.CreateDataFormat();
ICellStyle style1 = wk.CreateCellStyle();
style1.DataFormat = dataformat.GetFormat("text");
sheet.SetDefaultColumnStyle(0, style1);//列格式
HSSFRow row = (HSSFRow)sheet.CreateRow(0);
row.CreateCell(0).SetCellValue("0000005");
row.GetCell(0).CellStyle = style1;//单元格格式