using System.IO;
  using System.IO.Packaging;
  using System.Windows;
  using System.Windows.Documents;
  using System.Windows.Xps;
  using System.Windows.Xps.Packaging;
  
  namespace XAML_Example
  {
      public partial class MyDocument : System.Windows.Window
      {
          public MyDocument()
          {
              InitializeComponent();
          }
  
          void SaveToXPS(object sender, RoutedEventArgs e)
          {
              DocumentPaginator dp = 
         ((IDocumentPaginatorSource)flowDocumentReader1.Document).DocumentPaginator;
              Package pkg = Package.Open("myDocument.xps", FileMode.Create);
              XpsDocument xpsdoc = new XpsDocument(pkg);
  
              XpsDocumentWriter xpsWriter = 
                 XpsDocument.CreateXpsDocumentWriter(xpsdoc);
              xpsWriter.Write(dp);
  
              xpsdoc.Close();
              pkg.Close();
          }
      }
  }