OpenXML大型数据集的excel非常慢

我使用OpenXml将大数据转换为excel，我使用以下导出到excel类

http://www.codeproject.com/Articles/692092/A-free-Export-to-Excel-Csharp-class-using-OpenXML

下面是我的类中的代码。

  public static bool CreateExcelDocumentAsStream(DataSet ds, string filename, System.Web.HttpResponse Response)
    {
        try
        {
            System.IO.MemoryStream stream = new System.IO.MemoryStream();
            using (SpreadsheetDocument document = SpreadsheetDocument.Create(stream, SpreadsheetDocumentType.Workbook, true))
            {
                WriteExcelFile(ds, document);
            }
            stream.Flush();
            stream.Position = 0;
            Response.ClearContent();
            Response.Clear();
            Response.Buffer = true;
            Response.Charset = "";
            //  NOTE: If you get an "HttpCacheability does not exist" error on the following line, make sure you have
            //  manually added System.Web to this project's References.
            Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);
            Response.AddHeader("content-disposition", "attachment; filename=" + filename);
            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            byte[] data1 = new byte[stream.Length];
            stream.Read(data1, 0, data1.Length);
            stream.Close();
            Response.BinaryWrite(data1);
            Response.Flush();
            //  Feb2015: Needed to replace "Response.End();" with the following 3 lines, to make sure the Excel was fully written to the Response
            System.Web.HttpContext.Current.Response.Flush();
            System.Web.HttpContext.Current.Response.SuppressContent = true;
            System.Web.HttpContext.Current.ApplicationInstance.CompleteRequest();
            return true;
        }
        catch (Exception ex)
        {
            Trace.WriteLine("Failed, exception thrown: " + ex.Message);
            return false;
        }
    }
    /// <summary>
    /// Create an Excel file, and write it to a file.
    /// </summary>
    /// <param name="ds">DataSet containing the data to be written to the Excel.</param>
    /// <param name="excelFilename">Name of file to be written.</param>
    /// <returns>True if successful, false if something went wrong.</returns>
    public static bool CreateExcelDocument(DataSet ds, string excelFilename)
    {
        try
        {
            using (SpreadsheetDocument document = SpreadsheetDocument.Create(excelFilename, SpreadsheetDocumentType.Workbook))
            {
                WriteExcelFile(ds, document);
            }
            Trace.WriteLine("Successfully created: " + excelFilename);
            return true;
        }
        catch (Exception ex)
        {
            Trace.WriteLine("Failed, exception thrown: " + ex.Message);
            return false;
        }
    }

    private static void WriteExcelFile(DataSet ds, SpreadsheetDocument spreadsheet)
    {
        //  Create the Excel file contents.  This function is used when creating an Excel file either writing 
        //  to a file, or writing to a MemoryStream.
        spreadsheet.AddWorkbookPart();
        spreadsheet.WorkbookPart.Workbook = new DocumentFormat.OpenXml.Spreadsheet.Workbook();
        //  My thanks to James Miera for the following line of code (which prevents crashes in Excel 2010)
        spreadsheet.WorkbookPart.Workbook.Append(new BookViews(new WorkbookView()));
        //  If we don't add a "WorkbookStylesPart", OLEDB will refuse to connect to this .xlsx file !
        WorkbookStylesPart workbookStylesPart = spreadsheet.WorkbookPart.AddNewPart<WorkbookStylesPart>("rIdStyles");
        Stylesheet stylesheet = new Stylesheet();
        workbookStylesPart.Stylesheet = stylesheet;

        //  Loop through each of the DataTables in our DataSet, and create a new Excel Worksheet for each.
        uint worksheetNumber = 1;
        Sheets sheets = spreadsheet.WorkbookPart.Workbook.AppendChild<Sheets>(new Sheets());
        foreach (DataTable dt in ds.Tables)
        {
            //  For each worksheet you want to create
            string worksheetName = dt.TableName;
            //  Create worksheet part, and add it to the sheets collection in workbook
            WorksheetPart newWorksheetPart = spreadsheet.WorkbookPart.AddNewPart<WorksheetPart>();
            Sheet sheet = new Sheet() { Id = spreadsheet.WorkbookPart.GetIdOfPart(newWorksheetPart), SheetId = worksheetNumber, Name = worksheetName };
            // If you want to define the Column Widths for a Worksheet, you need to do this *before* appending the SheetData
            // http://social.msdn.microsoft.com/Forums/en-US/oxmlsdk/thread/1d93eca8-2949-4d12-8dd9-15cc24128b10/
            sheets.Append(sheet);
            //  Append this worksheet's data to our Workbook, using OpenXmlWriter, to prevent memory problems
            WriteDataTableToExcelWorksheet(dt, newWorksheetPart);
            worksheetNumber++;
        }

        spreadsheet.WorkbookPart.Workbook.Save();

    }
    private static void WriteDataTableToExcelWorksheet(DataTable dt, WorksheetPart worksheetPart)
    {
        OpenXmlWriter writer = OpenXmlWriter.Create(worksheetPart, Encoding.ASCII);
        writer.WriteStartElement(new Worksheet());
        writer.WriteStartElement(new SheetData());
        string cellValue = "";
        //  Create a Header Row in our Excel file, containing one header for each Column of data in our DataTable.
        //
        //  We'll also create an array, showing which type each column of data is (Text or Numeric), so when we come to write the actual
        //  cells of data, we'll know if to write Text values or Numeric cell values.
        int numberOfColumns = dt.Columns.Count;
        bool[] IsNumericColumn = new bool[numberOfColumns];
        bool[] IsDateColumn = new bool[numberOfColumns];
        string[] excelColumnNames = new string[numberOfColumns];
        for (int n = 0; n < numberOfColumns; n++)
            excelColumnNames[n] = GetExcelColumnName(n);
        //
        //  Create the Header row in our Excel Worksheet
        //
        uint rowIndex = 1;
        writer.WriteStartElement(new Row { RowIndex = rowIndex });
        for (int colInx = 0; colInx < numberOfColumns; colInx++)
        {
            DataColumn col = dt.Columns[colInx];
            AppendTextCell(excelColumnNames[colInx] + "1", col.ColumnName, ref writer);
            IsNumericColumn[colInx] = (col.DataType.FullName == "System.Decimal") || (col.DataType.FullName == "System.Int32") || (col.DataType.FullName == "System.Double") || (col.DataType.FullName == "System.Single");
            IsDateColumn[colInx] = (col.DataType.FullName == "System.DateTime");
        }
        writer.WriteEndElement();   //  End of header "Row"
        //
        //  Now, step through each row of data in our DataTable...
        //
        double cellNumericValue = 0;
        foreach (DataRow dr in dt.Rows)
        {
            // ...create a new row, and append a set of this row's data to it.
            ++rowIndex;
            writer.WriteStartElement(new Row { RowIndex = rowIndex });
            for (int colInx = 0; colInx < numberOfColumns; colInx++)
            {
                cellValue = dr.ItemArray[colInx].ToString();
                cellValue = ReplaceHexadecimalSymbols(cellValue);
                // Create cell with data
                if (IsNumericColumn[colInx])
                {
                    //  For numeric cells, make sure our input data IS a number, then write it out to the Excel file.
                    //  If this numeric value is NULL, then don't write anything to the Excel file.
                    cellNumericValue = 0;
                    if (double.TryParse(cellValue, out cellNumericValue))
                    {
                        cellValue = cellNumericValue.ToString();
                        AppendNumericCell(excelColumnNames[colInx] + rowIndex.ToString(), cellValue, ref writer);
                    }
                }
                else if (IsDateColumn[colInx])
                {
                    //  This is a date value.
                    DateTime dtValue;
                    string strValue = "";
                    if (DateTime.TryParse(cellValue, out dtValue))
                        strValue = dtValue.ToShortDateString();
                    AppendTextCell(excelColumnNames[colInx] + rowIndex.ToString(), strValue, ref writer);
                }
                else
                {
                    //  For text cells, just write the input data straight out to the Excel file.
                    AppendTextCell(excelColumnNames[colInx] + rowIndex.ToString(), cellValue, ref writer);
                }
            }
            writer.WriteEndElement(); //  End of Row
        }
        writer.WriteEndElement(); //  End of SheetData
        writer.WriteEndElement(); //  End of worksheet
        writer.Close();
    }
    private static void AppendTextCell(string cellReference, string cellStringValue, ref OpenXmlWriter writer)
    {
        //  Add a new Excel Cell to our Row 
        writer.WriteElement(new Cell
        {
            CellValue = new CellValue(cellStringValue),
            CellReference = cellReference,
            DataType = CellValues.String
        });
    }
    private static void AppendNumericCell(string cellReference, string cellStringValue, ref OpenXmlWriter writer)
    {
        //  Add a new Excel Cell to our Row 
        writer.WriteElement(new Cell
        {
            CellValue = new CellValue(cellStringValue),
            CellReference = cellReference,
            DataType = CellValues.Number
        });
    }
    private static string ReplaceHexadecimalSymbols(string txt)
    {
        string r = "['x00-'x08'x0B'x0C'x0E-'x1F'x26]";
        return Regex.Replace(txt, r, "", RegexOptions.Compiled);
    }

我像这样调用方法

            CreateExcelFile.CreateExcelDocumentAsStream(ds, ExportToExcel.FileName, response);

这是工作良好，但它有性能问题，它的速度非常慢。我的excel数据有49K行和100列。

有办法提高性能吗?

如有任何建议，不胜感激。

Thanks in advance