title: How to extract given page from a pdf file on iOS?
body: <p>i want to email current page of pdf on iOS.
  i think i must extract the page first.</p>
  
  <p>how can i extract/save a page from pdf file?
  i found this link:
  <a href="https://stackoverflow.com/questions/9238229/iphone-how-to-extract-the-pdf-pages-from-pdf-file-if-the-pdf-file-pdf-page-conta">https://stackoverflow.com/questions/9238229/iphone-how-to-extract-the-pdf-pages-from-pdf-file-if-the-pdf-file-pdf-page-conta</a></p>
  
  <p>(but i don't have HelperClass)</p>