title: WPF MVVM Authorization
body: <p>I'm trying to build an authorization mechanism for my WPF/MVVM app. Normally, I can easily place authorization check (i.e. a call to Authorization service/provider) in the OnStartUp() function of the View's code-behind. To adhere MVVM, however, is there any way to avoid making such a direct call in View, but in ViewModel class instead, so that the View's code-behind remains empty? Or what's the most effective way of implementing auth in WFP/MVVM?</p>
  
  <p>For example, let AuthProvider be a property of the ViewModel, which is bound to the View (as with other properties and commands). How can I proceed that binding in order to implement the authorization mechanism here? </p>
  
  <p>Thank you!</p>
  
  <p>cheers</p>