title: Self Updating a POCO Model class from external webservice
body: <p>I am working on a class library that tracks transit vehicles in close to real time using GPS lat/long co-ordinates.</p>
  
  <p>The library gets the vehicles positions from a rest XML web service provided by the transit service. I want the vehicle coordinates to automatically update them selves without having to manually call and update them through a refresh method in my application.  The class should automatically update itself with the latest data and raise an event when it updates. </p>
  
  <p>Is it possible to auto refresh the data on a timer inside of an object using a timed event or is this not possible with out running a message pump within the class</p>
  
  <p>I apologize if there is an existing question for this type of thing but if there is I couldn't find it using Google or the site search. </p>