Npoi 导出Excel 下拉列表异常: String literals in formulas can't be bigger than 255 Chars ASCII

代码:

 public static void dropDownList(string[] datas, string filePath)
 {
     HSSFWorkbook workbook = new HSSFWorkbook();
     ISheet sheet = workbook.CreateSheet("下拉列表测试");
     ISheet hidden = workbook.CreateSheet("hidden");
     //数据源sheet页不显示
      workbook.SetSheetHidden(workbook.GetSheetIndex(hidden), true);
     ICellStyle style = workbook.CreateCellStyle();
     style.DataFormat = HSSFDataFormat.GetBuiltinFormat("");
     style.Alignment = HorizontalAlignment.Center;
     style.VerticalAlignment = VerticalAlignment.Center;
     IRow row = null;
     ICell cell = null;
     for (int i = ; i < datas.Length; i++)
     {
         row = hidden.CreateRow(i);
         cell = row.CreateCell();
         cell.SetCellValue(datas[i]);
     }
     IName namedCell = workbook.CreateName();
     namedCell.NameName = "hidden";
     namedCell.RefersToFormula = "hidden!A$1:A$" + datas.Length;
     HSSFDataValidationHelper dvHelper = new HSSFDataValidationHelper(sheet as HSSFSheet);
     IDataValidationConstraint dvConstraint = (IDataValidationConstraint)dvHelper.CreateFormulaListConstraint("hidden");
     CellRangeAddressList addressList = null;
     HSSFDataValidation validation = null;
     for (int i = ; i < datas.Length; i++)
     {
         row = sheet.CreateRow(i);
         cell = row.CreateCell();
         cell.CellStyle = style;
         addressList = new CellRangeAddressList(i, i, , );
         validation = (HSSFDataValidation)dvHelper.CreateValidation(dvConstraint, addressList);
         sheet.AddValidationData(validation);
     }

     FileStream stream = new FileStream(filePath, FileMode.OpenOrCreate);
     workbook.Write(stream);
     stream.Close();
 }        

调用:

 static void Main(string[] args)
 {
     int max = ;
     string[] datas = new string[max];
     for (int i = ; i < max; i++)
     {
         datas[i] = "" + i;
     }

     string filePath = @"F:\\test.xls";
     dropDownList(datas, filePath);

     Console.Read();
 }