title: Ctrl key press condition in WPF MouseLeftButtonDown event-handler
body: <p>How I can add an additional condition for a certain keyboard key, to a WPF <code>MouseLeftButtonDown</code> event-handler?</p>
  
  <p>For example <kbd>Ctrl</kbd> + key </p>
  
  <pre><code>private void Grid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
  {         
      ...
  }
  </code></pre>