FlowDocument（.xaml）->XpsDocument->DocumentViewer

public void LoadXps()
{
            //构造一个基于内存的xps document
            MemoryStream ms = new MemoryStream();
            Package package = Package.Open(ms, FileMode.Create, FileAccess.ReadWrite);
            Uri DocumentUri = new Uri("pack://InMemoryDocument.xps");
            PackageStore.RemovePackage(DocumentUri);
            PackageStore.AddPackage(DocumentUri, package);
            XpsDocument xpsDocument = new XpsDocument(package, CompressionOption.Fast, DocumentUri.AbsoluteUri);
            //将flow document写入基于内存的xps document中去
            XpsDocumentWriter writer = XpsDocument.CreateXpsDocumentWriter(xpsDocument);
            writer.Write(((IDocumentPaginatorSource)m_doc).DocumentPaginator);
            //获取这个基于内存的xps document的fixed document
            docViewer.Document = xpsDocument.GetFixedDocumentSequence();
            //关闭基于内存的xps document
            xpsDocument.Close();
}