CODEWITHSUNDEEP
asp.net.netpdfpdfsharp
Anderson
Anderson

Reputation: 144

PDFSharp seems to be failing to open certain PDF documents

I have a program that adds a second page to PDFs submitted to the website. I use C# and PDFSharp. Most documents work fine, but a few users are getting "Object reference not set to an instance of an object."

using PdfSharp;
using PdfSharp.Drawing;
using PdfSharp.Pdf;
using PdfSharp.Pdf.IO;
using PdfSharp.Drawing.Layout;

PdfDocument rosterInput = PdfReader.Open(FilePath, PdfDocumentOpenMode.Import);

PdfPage rpage = rosterInput.Pages[0];

The error occurs on the second line. When I debug, it says PageCount = 0, which is weird because it is a 1 page document.

Upvotes: 1

Views: 21344

Answers (2)

Bernardo Duhne
Bernardo Duhne

Reputation: 11

Thank you very much you saved my day!, my only suggestion to improve the solution is to use the memorystream inside on a using block like this:

  Using memoryStream As MemoryStream = ReturnCompatiblePdf(File.FullName)
      Dim DocPdf As PdfDocument = PdfReader.Open(memoryStream, PdfDocumentOpenMode.Import)
      //Your code here.....
  End Using

Upvotes: 1

Guest
Guest

Reputation: 19

I had the same issue but resolved by the below code, issue was by PDF compatibility. 

PdfSharp.Pdf.IO.PdfReader.Open(ReturnCompatiblePdf("PDF FILE PATH"), PdfSharp.Pdf.IO.PdfDocumentOpenMode.Import)


Private Function ReturnCompatiblePdf(ByVal sFilename As String) As MemoryStream

    Dim reader As New iTextSharp.text.pdf.PdfReader(sFilename)
    Dim output_stream As New MemoryStream

    ' we retrieve the total number of pages
    Dim n As Integer = reader.NumberOfPages
    ' step 1: creation of a document-object
    Dim document As New iTextSharp.text.Document(reader.GetPageSizeWithRotation(1))
    ' step 2: we create a writer that listens to the document
    Dim writer As iTextSharp.text.pdf.PdfWriter = iTextSharp.text.pdf.PdfWriter.GetInstance(document, output_stream)
    'write pdf that pdfsharp can understand
    writer.SetPdfVersion(iTextSharp.text.pdf.PdfWriter.PDF_VERSION_1_4)
    ' step 3: we open the document
    document.Open()
    Dim cb As iTextSharp.text.pdf.PdfContentByte = writer.DirectContent
    Dim page As iTextSharp.text.pdf.PdfImportedPage

    Dim rotation As Integer

    Dim i As Integer = 0
    While i < n
        i += 1
        document.SetPageSize(reader.GetPageSizeWithRotation(i))
        document.NewPage()
        page = writer.GetImportedPage(reader, i)
        rotation = reader.GetPageRotation(i)
        If rotation = 90 OrElse rotation = 270 Then
            cb.AddTemplate(page, 0, -1.0F, 1.0F, 0, 0, _
            reader.GetPageSizeWithRotation(i).Height)
        Else
            cb.AddTemplate(page, 1.0F, 0, 0, 1.0F, 0, _
            0)
        End If
    End While

    '---- Keep the stream open!
    writer.CloseStream = False

    ' step 5: we close the document
    document.Close()

    Return output_stream

End Function

Upvotes: 0

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