WPF: How to handle errors with a BackgroundWorker

I am a bit of a newbie when it comes to windows client programming. I have a background worker that has a DoWork event and a RunCompleted event wired up. If an exception gets thrown in DoWork, I want to make changes to my UI, however, I cant because it is in a different thread. I can communicate the error to RunCompleted, but that doesn't help me either.

From stackoverflow

• call Dispatcher.BeginInvoke. Basically, you want code like this:

  void UpdateState(WhatEverType someObject)
  {
      if (! Dispatcher.CheckAccess())
      {
          Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(()=>UpdateState(someObject));
      }
      else
      {
          //make the UI changes here.
      }
  }
  

  Matt Briggs : Very good answer, I like the way it calls itself through the dispatcher. Thank you :)