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();
        }
    }
}