Hi ,

Thanks for your Reply.

I am using LOB of SilverLight Netadvantage. Version is 10.3.20103.1006.
Now i am writing into MemoryStream and then writing back to File. But still Format is not applied.
I have attached the code below. please check and let me know the issue and resolution.

 string path = System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath + @"Export\" + "ABC.xls";
            FileStream file1 = new FileStream(path, FileMode.Create, FileAccess.Write);
            MemoryStream memStream = new MemoryStream();

            #region "Create a file using Stream"
                try
                {
                    WorkbookFormat workbookFormat = WorkbookFormat.Excel97To2003;
                    // create an Excel workbook in the specified format
                    Workbook dataWorkbook = new Workbook(workbookFormat);
                    // create the Excel worksheet to receive the export data
                    Worksheet worksheet = dataWorkbook.Worksheets.Add(worksheetName);
                    // freeze header row
                    worksheet.DisplayOptions.PanesAreFrozen = true;
                    worksheet.DisplayOptions.FrozenPaneSettings.FrozenRows = 1;

                    #region "Header Row"
                    worksheet.DefaultColumnWidth = 5000;
                    int currentColumn = 0;
                    foreach (DataColumn column in result.Columns)
                    {
                        string format = GetFormatForColumn(column.ColumnName);
                        worksheet.Rows[0].CellFormat.FormatString = format;
                        this.SetCellValue(worksheet.Rows[0].Cells[currentColumn], column.ColumnName, null);
                        currentColumn++;
                    }
                    #endregion

                    int currentRow = 1;
                    foreach (DataRow row in result.Rows)
                    {
                        int currentCell = 0;
                        foreach (DataColumn col in result.Columns)
                        {
                            this.SetCellValue(worksheet.Rows[currentRow].Cells[currentCell], row[col.ColumnName], col.DataType);
                            currentCell++;
                        }
                        currentRow++;
                    }
                    dataWorkbook.Save(memStream);
                    byte[] data = memStream.ToArray();
                    file1.Write(data, 0, data.Length);
                    file1.Close();
                }
                catch (Exception ex)
                {
                    string msg = ex.InnerException.Message;
                }
            #endregion

Thanks

Anil Kumar