title: ViewModel and Singleton Pattern
body: <p>I have one <code>ViewModel</code> for enums handling (few entities in Entity Framework).</p>
  
  <p>1) Philosophically, is it a good practice to use a SINGLETON PATTERN for this ViewModel, because it's widespread over all application and it's used on many places.</p>
  
  <p>2) Isn't it a problem for ViewModel (and associated <code>ObjectContext</code>) to live for very long time?</p>
  
  <p>Thank you!</p>