File Attachment using Memory stream in D365 F&O AX 2012

In Dynamics Ax we normally came across file attachment of file. In my example I am attaching File that has been received in Memory stream. 

public void attachFile(str _file, PurchLine _purchline, CMTTankId _tankId, System.IO.MemoryStream _streamFile, DocuTypeId _DocType)

    {

        str                 pdfFile;

        DocuRef             docuref;

        System.Exception    ex;

        pdfFile     = _file+fileExt;

        try

        {

            _streamFile.Seek(0, System.IO.SeekOrigin::Begin);

            docuref = DocumentManagement::attachFileToCommon(_PurchLine,_DocType,_streamFile,                                       pdfFile, pdf,pdfFile);

        }

        catch (Exception::CLRError)

        {

            ex = ClrInterop::getLastException();

            if (ex != null)

            {

                ex = ex.get_InnerException();

                if (ex != null)

                {

                    error(ex.ToString());

                }

            }

        }

        catch (Exception::Error)

        {

            throw Exception::Error;

            

        }

    }

Note : Here is the Screenshot of the above code