NPOI 导出Excel表报错

当导出2007格式的时候，打开文件总是报错“发现 xxx中的部分内容有问题。是否让我们尽量尝试恢复？”。

导出的程序：

protected void btnValidateInternalData_Click(object sender, EventArgs e)
        {
            if (!FileUploadEmployee.HasFile)
            {
                ShowMessage("请先选择文件。");
                return;
            }

            var employeeData = GetDataTable();
            if (employeeData.Rows.Count == 0)
            {
                ShowMessage("文件数据为空。");
                return;
            }

            ValidateEmployeeField(employeeData);

            var fileName = FileUploadEmployee.FileName;
            DataSet dataSet = new DataSet();
            dataSet.Tables.Add(employeeData);
            byte[] fileBinary = null;
            fileBinary = ExcelHelper.ExportToExcel(dataSet, DataFormat.Excel2007);
            var reportFileName = Path.GetFileNameWithoutExtension(fileName) + "Validated" + DateTime.Now.ToString("yyyyMMddHHmmss") + Path.GetExtension(fileName);
            Response.Buffer = true;
            Response.Clear();
            Response.ClearHeaders();
            Response.ClearContent();
            Response.AddHeader("Content-Disposition", @"attachment;filename=""" + reportFileName + @"""");
            Response.AddHeader("Content-Length", fileBinary.Length.ToString());
            Response.ContentType = "application/vnd.ms-excel"; //"application/octet-stream"; 
            Response.BinaryWrite(fileBinary);
            //说明：当仅使用Response.End()发送缓冲输出时，打开导出的excel会出现 部分内容有问题 的错误。
            Response.Flush();//向客户端发送当前所有缓冲的输出。
            Response.End();//将当前所有缓冲的输出发送到客户端，停止该页的执行，并引发 EndRequest 事件。
        }

从dataset创建excel表格的方法：

 public static byte[] ExportToExcel(DataSet origDataSet, DataFormat dataFormat, string culture = "", bool shouldCheckHideColumnsForReport = false)
        {
            IWorkbook workbook = null;
            switch (dataFormat)
            {
                case DataFormat.Excel97_2003:
                    workbook = new HSSFWorkbook();
                    break;
                case DataFormat.Excel2007:
                    workbook = new XSSFWorkbook();
                    break;
            }

            ICellStyle cellstyleDate = workbook.CreateCellStyle();
            short df = workbook.CreateDataFormat().GetFormat(DateUtils.FORMAT_DATETIME);
            if (culture == new Language(LanguageEnum.zhcn).Code)
                df = workbook.CreateDataFormat().GetFormat(DateUtils.FORMAT_DATETIME);
            cellstyleDate.DataFormat = df;

            foreach (DataTable dt in origDataSet.Tables)
            {
                ISheet sheet = workbook.CreateSheet(dt.TableName);
                
                int columnIndex = 0;
                IRow row = sheet.CreateRow(0);
                ICell cell;
                foreach (DataColumn dc in dt.Columns)
                {
                    string columnName = dc.ColumnName;
                    if (shouldCheckHideColumnsForReport && ShouldSkipColumnForReport(columnName))
                    {
                        //dont add this column in this external report
                        continue;
                    }
                    cell = row.CreateCell(columnIndex);
                    cell.SetCellValue(dc.ColumnName);

                    columnIndex++;
                }

                List<int> lockedColumnList = new List<int>();
                int rowIndex = 1;
                foreach (DataRow dr in dt.Rows)
                {
                    row = sheet.CreateRow(rowIndex);
                    columnIndex = 0;
                    foreach (DataColumn dc in dt.Columns)
                    {
                        string columnName = dc.ColumnName;
                        if (shouldCheckHideColumnsForReport && ShouldSkipColumnForReport(columnName))
                        {
                            //dont add this column in this external report
                            continue;
                        }
                        cell = row.CreateCell(columnIndex);
                        
                        if (dc.DataType == Type.GetType("System.DateTime"))
                        {
                            DateTime dateTime = DateTime.MinValue;
                            if (DateTime.TryParse(dr[columnName].ToString(), out dateTime))
                            {
                                cell.CellStyle = cellstyleDate;
                                cell.SetCellValue(dateTime);
                            }
                            else
                                cell.SetCellValue(dr[columnName].ToString());
                        }
                        else if (dc.DataType == Type.GetType("System.Decimal"))
                        {
                            double decimalValue = 0;
                            if (double.TryParse(dr[columnName].ToString(), out decimalValue))
                            {
                                cell.SetCellValue(decimalValue);
                            }
                            else
                                cell.SetCellValue(dr[columnName].ToString());
                        }
                        else
                        {
                            string columnValue = dr[columnName].ToString();
                            cell.SetCellValue(columnValue);
                        }
                        columnIndex++;
                    }
                    rowIndex++;
                }
            }

Response.Flush() Response.End()的区别

//Response.Flush() 将缓存中的内容立即显示出来
//Response.End()  缓冲的输出发送到客户端  停止页面执行
//例:
//Response.Write("520");
//Response.End(); \执行到这里结束页面显示"520" 下面的语句不再执行 (和没写一样)
//Response.Write("025");

//如果是Response.Flush() 将缓存中的内容立即显示出来,然后再执行后面的语句