I am using this method to get total pages of a PDF file:
Code:
public static Int32 CountPages(String filename)
{
using(PdfSharp.Pdf.PdfDocument inputDocument = PdfSharp.Pdf.IO.PdfReader.Open(filename, PdfSharp.Pdf.IO.PdfDocumentOpenMode.InformationOnly))
{
return inputDocument.PageCount;
}
}
The "InformationOnly" parameter works fine. This is the first free library I have tested that can count pages of large PDF files (>300MB).
But when I run my application, the memory increases at first line of the method and don't down after the using, and in few seconds my application throws a OutOfMemoryException (on another part of my app).
So I looked for dispose method on PdfDocument and I get it:
Code:
public void Dispose()
{
Dispose(true);
//GC.SuppressFinalize(this);
}
void Dispose(bool disposing)
{
if (this.state != DocumentState.Disposed)
{
if (disposing)
{
// Dispose managed resources.
}
//PdfDocument.Gob.DetatchDocument(Handle);
}
this.state = DocumentState.Disposed;
}
(PdfDocument.cs lines 151..168)
Its appears that is not disposing anything. So I've debugged the Open() method on PdfReader class and see memory increasing at this loop:
Code:
// Read all indirect objects
for (int idx = 0; idx < count; idx++)
{
PdfReference iref = irefs[idx];
if (iref.Value == null)
{
try
{
Debug.Assert(document.irefTable.Contains(iref.ObjectID));
PdfObject pdfObject = parser.ReadObject(null, iref.ObjectID, false);
Debug.Assert(pdfObject.Reference == iref);
pdfObject.Reference = iref;
Debug.Assert(pdfObject.Reference.Value != null, "something got wrong");
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
else
{
Debug.Assert(document.irefTable.Contains(iref.ObjectID));
iref.GetType();
}
// Set maximum object number
document.irefTable.maxObjectNumber = Math.Max(document.irefTable.maxObjectNumber, iref.ObjectNumber);
}
(PdfReader.cs lines 346..372)
It is not clear to me which object is retaining data in memory.
Do anyone knows how to correctly dispose PdfDocument?
Login
Register
FAQ
Search
