InvalidateRequerySuggested on GUI Thread

I've been having issues where buttons weren't getting enabled on my WPF application, only by clicking the form would they work.

I found that I need to force the refresh using CommandManager.InvalidateRequerySuggested but that didn't work, the reason being I wasn't on the GUI Thread, I was on another thread, so here is my little helper class to do it.

 public static void RaiseInvalidateRequerySuggested()
 {
      Dispatcher dispatcher = null;

      if (Application.Current != null)
       {
          dispatcher = Application.Current.Dispatcher;
        }

       if (dispatcher != null && !dispatcher.CheckAccess())
        {
         dispatcher.BeginInvoke(DispatcherPriority.Normal,(Action)CommandManager.InvalidateRequerySuggested);
         }
 }

This tries to get the application, then gets the dispatcher for the application, makes sure you have access, and then dispatches the Invalidate to that thread.

bingo.