ssrs to byte and byte to pdf in memory - asp.net

Question

I am trying to copy ssrs report to pdf in memory but i am getting error message when i open pdf 'file not in right format' . I am using asp.net and iTextSharp.
I want to copy ssrs to new pdf (rptpdf) file in memory and then open existing pdf and copy images to second page of that (rptpdf) pdf.
For testing purpose i am trying to see if i can copy ssrs to pdf.
Dim doc As New iTextSharp.text.Document()
Dim content As Byte()
Try
Using myMemoryStream As New MemoryStream()
Dim writer As iTextSharp.text.pdf.PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(doc, myMemoryStream)
doc.Open()
Dim cb As iTextSharp.text.pdf.PdfContentByte = writer.DirectContent
Dim page As iTextSharp.text.pdf.PdfImportedPage
'--- bytes = rptViewer.ServerReport.Render("PDF", "", "", "", "", Nothing, Nothing)
Dim b() As Byte = ReportRender.GetReport()
Dim reader2 As New iTextSharp.text.pdf.PdfReader(b)
Dim pages As Integer = reader2.NumberOfPages
For i As Integer = 1 To pages
doc.SetPageSize(iTextSharp.text.PageSize.LETTER)
doc.NewPage()
page = writer.GetImportedPage(reader2, i)
cb.AddTemplate(page, 0, 0)
Next
doc.Close()
reader2.Close()
writer.Close()
content = myMemoryStream.ToArray()
myMemoryStream.Close()
End Using
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=" & "hello" & ".pdf")
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.Write(content)
UPDATED
I have managed to copy reportviewer report byte to memory stream but at add pdf file (line "writer.AddPage(page)") i get error 'object not reference '
Using myMemoryStream As New MemoryStream()
Dim rptpdfwriter As iTextSharp.text.pdf.PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(doc, myMemoryStream)
If rptpdfwriter Is Nothing Then
Return
End If
doc.Open()
Dim cb As iTextSharp.text.pdf.PdfContentByte = rptpdfwriter.DirectContent
Dim page2 As iTextSharp.text.pdf.PdfImportedPage
'--- bytes = rptViewer.ServerReport.Render("PDF", "", "", "", "", Nothing, Nothing)
Dim b() As Byte = ReportRender.GetReport()
Dim reader2 As New iTextSharp.text.pdf.PdfReader(b)
Dim pages2 As Integer = reader2.NumberOfPages
For i As Integer = 1 To pages2
doc.SetPageSize(iTextSharp.text.PageSize.A4.Rotate)
doc.NewPage()
page2 = rptpdfwriter.GetImportedPage(reader2, i)
cb.AddTemplate(page2, 0, 0)
Next
reader2.Close()
For Each item As Expenses In expenses
Select Case item.Ext.ToLower
Case ".pdf"
Dim writer As New iTextSharp.text.pdf.PdfCopy(doc, myMemoryStream)
Dim reader As New iTextSharp.text.pdf.PdfReader(Server.MapPath("/docs/expenses/" + item.ExpenseID.ToString + item.Ext))
reader.ConsolidateNamedDestinations()
For i As Integer = 1 To reader.NumberOfPages
Dim page As iTextSharp.text.pdf.PdfImportedPage = writer.GetImportedPage(reader, i)
writer.AddPage(page)
Next
Dim form As iTextSharp.text.pdf.PRAcroForm = reader.AcroForm
If form IsNot Nothing Then
writer.CopyAcroForm(reader)
End If
reader.Close()
Case ".jpg"
Dim pdfWriter As iTextSharp.text.pdf.PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(doc, myMemoryStream)
Dim jpg As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(Server.MapPath("/docs/expenses/" + item.ExpenseID.ToString + item.Ext))
If Not doc.IsOpen Then doc.Open()
doc.Add(jpg)
Case Else
Exit Sub
End Select
Next
doc.Close()
Content = myMemoryStream.ToArray()
myMemoryStream.Flush()
myMemoryStream.Dispose()
Response.ContentType = "application/pdf"
Response.AppendHeader("Content-Disposition", "attachment; filename=LeftCorneraaa.pdf")
Response.BinaryWrite(Content)
End Using