I am not able to protect the worksheet. Can you please post the snippet.

Thanks,

Mani.

Is it something to do with the version and I am using Infragistics2.Excel.v7.3?

I am not able to protect worksheet.

I don't believe the version should matter. The ability to protect worksheets has been in the Excel assembly since it was introduced. 

In what version of Excel are you opening the workbook?

I am using Excel 2000 and also I am using memorystream to allow the user to save the excel file.

            MemoryStream ms = new MemoryStream();           
            wb.Save(ms);
            Byte[] byteArr = (Byte[])Array.CreateInstance(typeof(Byte),ms.Length);
            ms.Position  = 0;
            ms.Read(byteArr,0,(int)ms.Length);
            ms.Close();
            Response.Clear();
            Response.ContentType = "application/vnd.ms-excel";
            Response.AddHeader("Content-Disposition", "attachment;filename=DocTypeInfo.xls");
            Response.BinaryWrite(byteArr);          
            Response.End();

Following are the snippet I am using:

            Infragistics.Excel.Workbook wb = new Infragistics.Excel.Workbook();
            Infragistics.Excel.Worksheet sheet = wb.Worksheets.Add("ExpenseAllocation");
            sheet.Protected = true;
            wb.Protected = true;

            sheet.DisplayOptions.PanesAreFrozen = false;
            sheet.Rows[0].CellFormat.Font.Bold = Infragistics.Excel.ExcelDefaultableBoolean.True;
            sheet.Rows[0].CellFormat.FillPattern = Infragistics.Excel.FillPatternStyle.Solid;
            sheet.Rows[0].CellFormat.FillPatternForegroundColor = System.Drawing.Color.FromArgb(238, 243, 255);

            Infragistics.Excel.WorksheetRow headersRow = sheet.Rows[0];
            headersRow.Cells[0].Value = "Order ID";
            headersRow.Cells[1].Value = "Product";
            headersRow.Cells[2].Value = "Unit Price";
            headersRow.Cells[3].Value = "Quantity";
            headersRow.Cells[4].Value = "Discount";
            headersRow.Cells[5].Value = "Order Total";

            // The "Unit Price" column should display its values as dollars
            sheet.Columns[2].CellFormat.FormatString = "\"$\"#,##0.00_);(\"$\"#,##0.00)";
            // The "Discount" column should display its values as percentages
            sheet.Columns[4].CellFormat.FormatString = "0.00%";
            // The "Order Total" column should display its values as dollars
            sheet.Columns[5].CellFormat.FormatString = "\"$\"#,##0.00_);(\"$\"#,##0;00)";
            // Allow enough room to display the totals
            sheet.Columns[5].Width = 3000;

            Infragistics.Excel.WorksheetRow currentRow;

            currentRow = sheet.Rows[1];
            currentRow.Cells[0].Value = 10248;
            currentRow.Cells[1].Value = 42;
            currentRow.Cells[2].Value = 9.80;
            currentRow.Cells[3].Value = 10;
            currentRow.Cells[4].Value = 0.075;

            currentRow = sheet.Rows[2];
            currentRow.Cells[0].Value = 10248;
            currentRow.Cells[1].Value = 72;
            currentRow.Cells[2].Value = 34.80;
            currentRow.Cells[3].Value = 5;
            currentRow.Cells[4].Value = 0.075;

            currentRow = sheet.Rows[3];
            currentRow.Cells[0].Value = 10249;
            currentRow.Cells[1].Value = 14;
            currentRow.Cells[2].Value = 18.60;
            currentRow.Cells[3].Value = 9;
            currentRow.Cells[4].Value = 0.1;

            currentRow = sheet.Rows[4];
            currentRow.Cells[0].Value = 10249;
            currentRow.Cells[1].Value = 51;
            currentRow.Cells[2].Value = 42.40;
            currentRow.Cells[3].Value = 40;
            currentRow.Cells[4].Value = 0.1;

            MemoryStream ms = new MemoryStream();
            //wb.Save(@"c:\mani\test.xls");
            wb.Save(ms);
            Byte[] byteArr = (Byte[])Array.CreateInstance(typeof(Byte), ms.Length);
            ms.Position = 0;
            ms.Read(byteArr, 0, (int)ms.Length);
            ms.Close();
            Response.Clear();
            Response.ContentType = "application/vnd.ms-excel";
            Response.AddHeader("Content-Disposition", "attachment;filename=DocTypeInfo.xls");
            Response.BinaryWrite(byteArr);
            Response.End();

I tried using your code and the saved workbook file is correctly protected when it is opened in Excel 2000, Excel 2003, and Excel 2007. it's possible I have misunderstood the problem here. When I try to edit the cells with data, a message box appears for me telling me that the data cannot be edited. Are you not seeing this message or is there another problem you are experiencing?

Looks like it is something to do with the Infragistics.Excel version. Can you please send me your working copy of your sample. (entrie sample project)?

Thanks.

I have attached the sample, but version 7.3 is no longer supported so it is built with 8.1. You can remove that reference though and add the reference to 7.3 and it should work. If it does not work, I would recommend upgrading to the latest service release or a later version.