title: c# accessing ui elements in Task without using dispatcher
body: <p>I'm hoping to find a mechanism for accessing/manipulating a ui element (like textbox) properties in a separate Thread but accessing it using Dispatcher means giving control to UI thread which keeps the user from doing anything (which is something I don't want - to freeze ui..)</p>
  <p>So I actually want to access the ui from a separate thread without needing to freeze the main UI thread.</p>