Printing

Printing a PDF document comes down to rendering the PDF pages to a System.Drawing.Graphics object that represents a printer. So, basically the process is similar to rendering a PDF document to a raster image as described in Chapter 3. Nonetheless there are some points specif to printing PDF documents. These are discussed in this chapter.

Basic code sample

Here is the basic code sample of a console application that prints a PDF document to the default printer using default settings.

static int pageIndex = 0;
static Document document;

static void Main(string[] args)
{
   using (FileStream file = new FileStream(
      @"document.pdf", FileMode.Open, FileAccess.Read))
   {
      document = new Document(file);

      PrintDocument printDocument = new PrintDocument();
      printDocument.DocumentName = document.DocumentInfo.Title;

      printDocument.PrintPage += new PrintPageEventHandler(printPage);
      printDocument.Print();
   }
}

static void printPage(object sender, PrintPageEventArgs e)
{
   e.Graphics.PageUnit = GraphicsUnit.Point;
   Page page = document.Pages[pageIndex++];
   page.Draw(e.Graphics);
   e.HasMorePages = pageIndex < document.Pages.Count; 
}
Select the output printer

You can only print to printers that have a printer driver installed. The installed printers can be retrieved and selected using the following code:

PrinterSettings.StringCollection printerNames =
   PrinterSettings.InstalledPrinters;
// select the first printer
string printerName = printerNames[0];

using (FileStream file = new FileStream(
   @"document.pdf", FileMode.Open, FileAccess.Read))
{
   document = new Document(file);

   PrintDocument printDocument = new PrintDocument();
   printDocument.PrinterSettings.PrinterName = printerName;

   printDocument.DocumentName = document.DocumentInfo.Title;

   printDocument.PrintPage += new PrintPageEventHandler(printPage);
   printDocument.Print();
}
Select the output tray
static void Main(string[] args)
{
   using (FileStream file = new FileStream(
      @"document.pdf", FileMode.Open, FileAccess.Read))
   {
      document = new Document(file);

      PrintDocument printDocument = new PrintDocument();

      PrinterSettings.PaperSourceCollection paperSources = 
         printDocument.PrinterSettings.PaperSources;
      printDocument.PrinterSettings.DefaultPageSettings.PaperSource =
         paperSources[0];

      printDocument.DocumentName = document.DocumentInfo.Title;

      printDocument.PrintPage += new PrintPageEventHandler(printPage);
      printDocument.Print();
   }
}

static void printPage(object sender, PrintPageEventArgs e)
{
   e.Graphics.PageUnit = GraphicsUnit.Point;
   Page page = document.Pages[pageIndex++];
   page.Draw(e.Graphics);
   e.HasMorePages = pageIndex< document.Pages.Count; 
}
Scale and rotate to fit

A typical operation is to scale and rotate the source page to fit the output paper. This is done by applying a geometric transformation to the System.Drawing.Graphics object before rendering the PDF page. The following PrintPahge event handler shows how to do this:

void printPage( object sender, PrintPageEventArgs e )
{
   e.Graphics.PageUnit = GraphicsUnit.Point;

   Page page = document.Pages[ pageIndex++ ];

   autoPosition( 
      e.Graphics,
      ( e.PageSettings.PaperSize.Width * 72 ) / 100, 
      ( e.PageSettings.PaperSize.Height * 72 ) / 100,
      // As of .NET 2.0, you can use the printable area 
      // instead of the papersize.
      // ( e.PageSettings.PrintableArea.Width * 72 ) / 100, 
      // ( e.PageSettings.PrintableArea.Height * 72 ) / 100,
      page.Width, page.Height );

   page.Draw( e.Graphics )

   e.HasMorePages = pageIndex < document.Pages.Count; 
}

void autoPosition( Graphics graphics, double printerWidth, 
   double printerHeight, double pdfWidth, double pdfHeight )
{
   double scaleX = printerWidth / pdfWidth;
   double scaleY = printerHeight / pdfHeight;
   double scale = Math.Min( scaleX, scaleY );

   graphics.ScaleTransform( (float) scale, (float) scale );
   graphics.TranslateTransform( 
      (float) ( printerWidth - scale * pdfWidth ) / 2, 
      (float) ( printerHeight - scale * pdfHeight ) / 2 );
}
Control font substitution

Font substitution is discussed in detail in Text and Fonts.

Code samples

The following code samples are included in the distribution and are relevant to printing PDF documents:

  • PrintPDF

  • ScaledPrinting