title: Cannot get access to UI thread in WPF dll called from VB6 exe
body: <p>I have a VB6 exe that calls a WPF 4.0 dll.<br>
  In my WPF dll I have a background worker that needs to update the UI.<br>
  I cannot seem to get back to the UI thread because the Application.Current is null.</p>
  
  <pre><code>Application app = Application.Current;
  if (app != null)
  {
    Dispatcher disp = app.Dispatcher;
    if (disp != null)
    {
      if (!disp.CheckAccess())
      {
      }
      else
      {
      }
    }
  }
  </code></pre>
  
  <p>I've also tried Dispatcher.CurrentDispatcher but that also does not switch me to the UI thread.</p>
  
  <p>Does anyone know how to switch to the UI thread in WPF when a VB6 exe calls a WPF dll?</p>