title: Get file extension with a file that has multiple periods
body: <p>Getting the file extension in <strong>C#</strong> is very simple,</p>
  
  <pre><code>FileInfo file = new FileInfo("c:\\myfile.txt");
  MessageBox.Show(file.Extension); // Displays '.txt'
  </code></pre>
  
  <p>However I have files in my app with multiple periods.</p>
  
  <pre><code>FileInfo file = new FileInfo("c:\\scene_a.scene.xml");
  MessageBox.Show(file.Extension); // Displays '.xml'
  </code></pre>
  
  <p>I want to be able to extract the <code>.scene.xml</code> portion of the name.</p>
  
  <p><strong>Update</strong><br>
  The extension should also include the initial <code>.</code> </p>
  
  <p>How can I get this from <code>FileInfo</code>?</p>