title: C# Use Open File Dialog to explore contents of PDX (zip) file
body: <p>We use an industry standard file (PDX) that is basically a zip archive file with the extension changed.  I want to allow the user to first select a .pdx file and then allow them to select a file within the archive.  I found this <a href="https://stackoverflow.com/questions/37593357/c-sharp-openfiledialog-open-zip-folder-containing-single-file">answer</a> that shows a very clever way to achieve this using the OpenFileDialog.  It works great if the archive has the .zip extension.  The problem is when the extension of the archive file is changed to .pdx then the open file dialog will not show the contents of the .pdx file.</p>
  <p>Is there a way to achieve this functionality with the OpenFileDialog?  I do not want to create my own dialog if there is a simple solution.</p>