void SaveQuestionToExcel(List datas, string path)
{

        using (Workbook workbook = new HSSFWorkbook())  
        {  
            var sheet = workbook.CreateSheet();  
            //表格头样式  
            CellStyle headerStyle = workbook.CreateCellStyle();  
            Font newFont = workbook.CreateFont();

            newFont.Boldweight = short.MaxValue;  
            newFont.FontHeightInPoints = 12;

            headerStyle.SetFont(newFont);  
            headerStyle.Alignment = HorizontalAlignment.CENTER;  
            headerStyle.FillPattern = FillPatternType.NO\_FILL;

            HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);

            headerRow.CreateCell(0).SetCellValue("题型");  
            headerRow.CreateCell(1).SetCellValue("试题内容");  
            headerRow.CreateCell(2).SetCellValue("试题答案");  
            headerRow.CreateCell(3).SetCellValue("难易度");  
            headerRow.CreateCell(4).SetCellValue("文件夹");  
            headerRow.CreateCell(5).SetCellValue("试题解析");

            headerRow.Cells.ForEach(x => x.CellStyle = headerStyle);

            int rowIndex = 1;  
            foreach (var quesItem in datas)  
            {

                HSSFRow row = (HSSFRow)sheet.CreateRow(rowIndex);  
                row.CreateCell(0).SetCellValue(quesItem.QuestionType);  
                row.CreateCell(1).SetCellValue(quesItem.ContentText);  
                row.CreateCell(2).SetCellValue(quesItem.AnswerText);  
                row.CreateCell(3).SetCellValue(((HardLevelEnum)quesItem.HardLevel).GetText());  
                row.CreateCell(4).SetCellValue(quesItem.FolderFullPath);  
                row.CreateCell(5).SetCellValue(quesItem.AnalysisText);

                rowIndex++;  
            }

            for (int i = 0; i < 6; i++)  
            {  
                sheet.AutoSizeColumn(i);

            }  
            FileStream streamFile = new FileStream(path, FileMode.Create);  
            MemoryStream streamMemory = new MemoryStream();

            workbook.Write(streamMemory);  
            byte\[\] data = streamMemory.ToArray();  
            streamFile.Write(data, 0, data.Length);

            // 清空缓冲区、关闭流  
            streamFile.Flush();  
            streamFile.Close();

            streamMemory.Close();  
            streamMemory.Dispose();  
        }  
    }