iTextSharp Created PDF is still in use

Question

If i create a pdf with the given source-code, i have the problem that i can not open the pdf-document for example in "adobe-acrobat" because it says that it is still in use by another process. What i am missing in my code to release the lock?

var a = Guid.NewGuid();

Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

PdfWriter writer2 = PdfWriter.GetInstance(pdfDoc, new FileStream(a.ToString()+".pdf", FileMode.Create));
writer2.SetFullCompression();
writer2.CloseStream = true;

iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(AppContext.BaseDirectory + "Ehrungsantrag.png");
img.SetAbsolutePosition(0, 0);
img.ScaleAbsoluteHeight(pdfDoc.PageSize.Height);
img.ScaleAbsoluteWidth(pdfDoc.PageSize.Width);
pdfDoc.Open();
pdfDoc.NewPage();
pdfDoc.Add(img);

pdfDoc.Close();
writer2.Close();

Answer 1

The error was not closed FileStream. Also as @Amy already mentioned, you need be sure that your clean up code is executed, for example like this:

Document pdfDoc = null;
PdfWriter writer2 = null;
System.IO.FileStream fs = null; // <- create the FileStream

try
{
   var a = Guid.NewGuid();
   pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

   fs =  new FileStream(a.ToString()+".pdf", FileMode.Create);
   writer2 = PdfWriter.GetInstance(pdfDoc, fs);
   writer2.SetFullCompression();
   writer2.CloseStream = true;

   iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(AppContext.BaseDirectory + "Ehrungsantrag.png");
   img.SetAbsolutePosition(0, 0);
   img.ScaleAbsoluteHeight(pdfDoc.PageSize.Height);
   img.ScaleAbsoluteWidth(pdfDoc.PageSize.Width);

   pdfDoc.Open();
   pdfDoc.NewPage();
   pdfDoc.Add(img);
}
finally
{
        pdfDoc.Close();
        pdfDoc = null;

        //writer2.Close(); 

       // That was the eroor -> always close open filehandles explicity !
       fs.Close(); 
}