Merging PDFs using iTextSharp removes Trim Box Detail - pdf

Question

I am trying to use iTextSharp to merge 2 or more PDF files. However I am not getting any details about the TrimBox. Performing the code below on the PDF (which was merged) always return NULL
Rectangle rect = reader.GetBoxSize(1, "trim");
This is the code for merging.
public void Merge(List<String> InFiles, String OutFile)
{
using (FileStream stream = new FileStream(OutFile, FileMode.Create))
using (Document doc = new Document())
using (PdfCopy pdf = new PdfCopy(doc, stream))
{
doc.Open();
PdfReader reader = null;
PdfImportedPage page = null;
InFiles.ForEach(file =>
{
reader = new PdfReader(file);
for (int i = 0; i < reader.NumberOfPages; i++)
{
page = pdf.GetImportedPage(reader, i + 1);
pdf.AddPage(page);
}
pdf.FreeReader(reader);
reader.Close();
});
}
}
How to keep I keep the box information after the merge?
-Alan-

Answer 1

Here is the code I created to merge Portrait and Landscape docs using iTextSharp. It works rather well.
public void MergeFiles(System.Collections.Generic.List<string> sourceFiles, string destinationFile)
{
Document document=null;
if (System.IO.File.Exists(destinationFile))
System.IO.File.Delete(destinationFile);
try
{
PdfCopy writer = null;
int numberOfPages=0;
foreach(string sourceFile in sourceFiles)
{
PdfReader reader = new PdfReader(sourceFile);
reader.ConsolidateNamedDestinations();
numberOfPages = reader.NumberOfPages;
if(document==null)
{
document = new Document(reader.GetPageSizeWithRotation(1));
writer = new PdfCopy(document, new FileStream(destinationFile, FileMode.Create));
document.Open();
}
for (int x = 1;x <= numberOfPages;x++ )
{
if (writer != null)
{
PdfImportedPage page = writer.GetImportedPage(reader, x);
writer.AddPage(page);
}
}
PRAcroForm form = reader.AcroForm;
if (form != null && writer != null)
writer.CopyAcroForm(reader);
}
}
finally
{
if (document != null && document.IsOpen())
document.Close();
}
}