title: Printing to PDF is fine, but printing to printer gives blank sheets (XPS Doc in WPF)
body: <p>To preface, my program has a <code>Frame</code> with multiple <code>Pages</code>. I store pages in a <code>List&lt;UIElement&gt;</code>, and use an XPS writer to print them.</p>
  <pre><code>        private void Print()
          {
              List&lt;UIElement&gt; Pages = new List&lt;UIElement&gt;();
  
              PrintDialog print = new PrintDialog();
              if (print.ShowDialog() == true)
              {
                  PageOne one = new PageOne();   // add a few pages for example's sake
                  Pages.Add(one);
  
                  PageTwo two = new PageTwo();
                  Pages.Add(two);
  
                  var xpsDocWriter = PrintQueue.CreateXpsDocumentWriter(print.PrintQueue);
                  PrintUIElements(xpsDocWriter, Pages);
              }
         }
  </code></pre>
  <p><code>PrintUIElements</code> is what writes to the XPS doc:</p>
  <pre><code>        private void PrintUIElements(XpsDocumentWriter xpsWriter, List&lt;UIElement&gt; uiElements)
          {
              var fixedDoc = new FixedDocument();
  
              foreach (UIElement element in uiElements)
              {
                  var fixedPage = new FixedPage();
                  var pageContent = new PageContent();
  
                  fixedPage.Children.Add(new Frame() { Content = element });
                  pageContent.Child = fixedPage;
  
                  fixedDoc.Pages.Add(pageContent);
              }
  
              xpsWriter.Write(fixedDoc);
          }
  </code></pre>
  <p>Like I said, printing to PDF via <code>PrintDialog</code> works perfectly, but choosing a printer causes it to print blank sheets. Any clues?</p>