This sample shows how to concatenate the pages of several PDF documents to one single file.
- When you add the same external page twice or more, the content of the pages is shared.
- Each imported page can be individually extended with graphics and text.
PDF Output File
See the PDF files created by this sample:
Variation 1 output.pdf (207 kB)
Variation 2 output.pdf (211 kB)
Variation 3 output.pdf (208 kB)
Variation 4 output.pdf (216 kB)
Screen Shots
Here is a sample screen shot of Variation 3:
Source Code
Here are code snippets for the 4 variations implemented in Concatenate Documents:
///
/// Imports all pages from a list of documents.
///
static void Variant1()
{
// Get some file names
string[] files = GetFiles();
// Open the output document
PdfDocument outputDocument = new PdfDocument();
// Iterate files
foreach (string file in files)
{
// Open the document to import pages from it.
PdfDocument inputDocument = PdfReader.Open(file, PdfDocumentOpenMode.Import);
// Iterate pages
int count = inputDocument.PageCount;
for (int idx = 0; idx < count; idx++)
{
// Get the page from the external document...
PdfPage page = inputDocument.Pages[idx];
// ...and add it to the output document.
outputDocument.AddPage(page);
}
}
// Save the document...
const string filename = "ConcatenatedDocument1_tempfile.pdf";
outputDocument.Save(filename);
// ...and start a viewer.
Process.Start(filename);
}
///
/// This sample adds each page twice to the output document. The output document
/// becomes only a little bit larger because the content of the pages is reused
/// and not duplicated.
///
static void Variant2()
{
// Get some file names
string[] files = GetFiles();
// Open the output document
PdfDocument outputDocument = new PdfDocument();
// Show consecutive pages facing. Requires Acrobat 5 or higher.
outputDocument.PageLayout = PdfPageLayout.TwoColumnLeft;
// Iterate files
foreach (string file in files)
{
// Open the document to import pages from it.
PdfDocument inputDocument = PdfReader.Open(file, PdfDocumentOpenMode.Import);
// Iterate pages
int count = inputDocument.PageCount;
for (int idx = 0; idx < count; idx++)
{
// Get the page from the external document...
PdfPage page = inputDocument.Pages[idx];
// ...and add them twice to the output document.
outputDocument.AddPage(page);
outputDocument.AddPage(page);
}
}
// Save the document...
const string filename = "ConcatenatedDocument2_tempfile.pdf";
outputDocument.Save(filename);
// ...and start a viewer.
Process.Start(filename);
}
///
/// This sample adds a consecutive number in the middle of each page.
/// It shows how you can add graphics to an imported page.
///
static void Variant3()
{
// Get some file names
string[] files = GetFiles();
// Open the output document
PdfDocument outputDocument = new PdfDocument();
// Note that the output document may look significant larger than in Variant1.
// This is because adding graphics to an imported page causes the
// uncompression of its content if it was compressed in the external document.
// To compare file sizes you should either run the sample as Release build
// or uncomment the following line.
//outputDocument.Options.CompressContentStreams = true;
XFont font = new XFont("Verdana", 40, XFontStyle.Bold);
int number = 0;
// Iterate files
foreach (string file in files)
{
// Open the document to import pages from it.
PdfDocument inputDocument = PdfReader.Open(file, PdfDocumentOpenMode.Import);
// Iterate pages
int count = inputDocument.PageCount;
for (int idx = 0; idx < count; idx++)
{
// Get the page from the external document...
PdfPage page = inputDocument.Pages[idx];
// ...and add it to the output document.
// Note that the PdfPage instance returned by AddPage is a
// different object.
page = outputDocument.AddPage(page);
// Create a graphics object for this page. To draw beneath the existing
// content set 'Append' to 'Prepend'.
XGraphics gfx = XGraphics.FromPdfPage(page, XGraphicsPdfPageOptions.Append);
DrawNumber(gfx, font, ++number);
}
}
// Save the document...
const string filename = "ConcatenatedDocument3_tempfile.pdf";
outputDocument.Save(filename);
// ...and start a viewer.
Process.Start(filename);
}
///
/// This sample is the combination of Variant2 and Variant3. It shows that you
/// can add external pages more than once and still add individual graphics on
/// each page. The external content is shared among the pages, the new graphics
/// are unique to each page. You can check this by comparing the file size
/// of Variant3 and Variant4.
///
static void Variant4()
{
// Get some file names
string[] files = GetFiles();
// Open the output document
PdfDocument outputDocument = new PdfDocument();
// For checking the file size uncomment next line.
//outputDocument.Options.CompressContentStreams = true;
XFont font = new XFont("Verdana", 40, XFontStyle.Bold);
int number = 0;
// Iterate files
foreach (string file in files)
{
// Open the document to import pages from it.
PdfDocument inputDocument = PdfReader.Open(file, PdfDocumentOpenMode.Import);
// Show consecutive pages facing. Requires Acrobat 5 or higher.
outputDocument.PageLayout = PdfPageLayout.TwoColumnLeft;
// Iterate pages
int count = inputDocument.PageCount;
for (int idx = 0; idx < count; idx++)
{
// Get the page from the external document...
PdfPage page = inputDocument.Pages[idx];
// ...and add it twice to the output document.
PdfPage page1 = outputDocument.AddPage(page);
PdfPage page2 = outputDocument.AddPage(page);
XGraphics gfx =
XGraphics.FromPdfPage(page1, XGraphicsPdfPageOptions.Append);
DrawNumber(gfx, font, ++number);
gfx = XGraphics.FromPdfPage(page2, XGraphicsPdfPageOptions.Append);
DrawNumber(gfx, font, ++number);
}
}
// Save the document...
const string filename = "ConcatenatedDocument4_tempfile.pdf";
outputDocument.Save(filename);
// ...and start a viewer.
Process.Start(filename);
}