title: Using Windows Explorer 'Print' context menu entry
body: <p>I have created a simple app for opening, viewing and printing PDF files. I want my app to be able to handle when a user right-clicks a PDF in explorer and selects 'print'. </p>
  
  <p>My app is registered as the default handler for PDF files.</p>
  
  <p>So, in short it should:</p>
  
  <ol>
  <li>Open the application</li>
  <li>Open the file</li>
  <li>Send print job to users default printer</li>
  <li>Close the app</li>
  </ol>
  
  <p>I can handle the opening, loading, printing and quitting no problem at all. I just don't know how to make my app aware that it has been triggered using this context sensitive 'print' option in explorer. I thought it would just be sent as an additional parameter, but I can't seem to trap it.</p>
  
  <p>Any ideas?</p>