title: filedescriptor use to render pdf file from external storage in android
body: <p>I have downloaded a pdf file in external storage directory and i want to reder it using pdfrender in android.
  i have successfully rendered the pdf saved in my asset folder but now i need to render the file that is saved in external directory. here is the code i am using</p>
  
  <p><code>String filePath1 = Environment.getExternalStorageDirectory().toString()+"/Mock-up Presentation.pdf";
  //filePath1 is the location for file i want to render
          File file = new File(filePath1);
          mFileDescriptor=getActivity().getAssets().openFd("sample.pdf").getParcelFileDescriptor();//sample pdf is saved in asset folder in project which i have rendered //already
          // This is the PdfRenderer we use to render the PDF.
          mPdfRenderer = new PdfRenderer(mFileDescriptor);</code></p>
  
  <p>Any help would be appreciated. </p>