title: Updating progressbar created on different thread
body: <p>I am currently trying to update a progress bar that is defined in another window that is created by a different thread.</p>
  <p>I need to send progress updates from the main thread in order to have the correct value displayed on progress bar.</p>
  <p>Any help is appreciated, thanks in advance. Below is the code:</p>
  <pre><code>  private void StartLoadingWindow(object sender, RoutedEventArgs e)
    {
       var t = new Thread(ThreadLoadingWindow); 
       t.SetApartmentState(ApartmentState.STA); //Mandatory
       t.Start();
    }
  
    private void ThreadLoadingWindow()
    {
       var w = new LoadingWindowsControl();
       w.Closed += (sender, args) =&gt;
       {
          //Exit Dispatcher when Window closes
          Dispatcher.CurrentDispatcher.BeginInvokeShutdown(DispatcherPriority.SystemIdle);
          Dispatcher.Run();
       };
       w.ShowDialog();
    }
  </code></pre>
  <p>Inside the LoadingWindowsControl I have created a simple mvvm progress bar.</p>