I am creating a PDF programmatically. The ActiveX component basically acts as a printer driver and I can't figure out how to know when it is done so I know the file exists for certain so I can read it into a byte array to store.

I am trying now to do this with system.io.filesystemwatcher but I can't seem to get the syntax right

Here is what I am playing around with :

  Public Function CreatePDFBytes(ByVal rtfstr As String) As Byte()

        ' PDFCreator has been created by the calling program

        ' create temporary directory and temporary filename

        Dim temppath As String = "c:\pdftemp"

        Dim fileBase As String = Path.GetFileNameWithoutExtension(Path.GetRandomFileName)
        Dim tempfile As String = fileBase & ".rtf"
        Dim tempfull As String = Path.Combine(temppath, tempfile)

        Dim temppdf As String = fileBase & ".pdf"
        Dim pdffull As String = Path.Combine(temppath, temppdf)


        ''-- Write out RTF
        File.WriteAllText(tempfull, rtfstr)

        '-- Convert to PDF and write to disk

        Dim pdfo As PDFCreator.clsPDFCreatorOptions

        pdfo = Me.Creator.cOptions

        '-- Setup options
        With pdfo
            .UseAutosave = 1
            .AutosaveFilename = temppdf
            ' .StartStandardProgram = 1
            .AutosaveDirectory = temppath

        End With

        Me.Creator.cOptions = pdfo

        Dim pdfbyte As Byte() = Nothing

        Using watcher As New FileSystemWatcher()

            watcher.Path = temppath
            watcher.Filter = "*.pdf"

            watcher.EnableRaisingEvents = True

' here is where i am confused 
' 
            Dim results As WaitForChangedResult

'this is the line that actually creates the pdf - it works, but my problem has been 
' if I don't wait until it is definitely created I'll get an error when I try to read it into
' the array.  If I step through and don't run the line to read the pdf to the byte array 
' until I see the file is definitely there, all is well
' as many as twenty files may be processed in a loop
' can't wrap my head around the sequence of the next two lines
' if I create first, I'm not waiting 
' if I wait first I time out before I'm creating

            Me.Creator.cPrintFile(tempfull)

            results = watcher.WaitForChanged(WatcherChangeTypes.Created, 20000)

            If results.TimedOut Then
' handle failure to create
            Else
' read the file into pdfbyte
           end if

        End Using

        Return pdfbyte

    End Function

Thoughts ?

TIA