title: Update UI from ViewModel class (MVVM pattern) in WPF
body: <p>I'm using the MVVM pattern in my first WPF app and have a problem with something quite basic I assume.</p>
  
  <p>When the user hits the "save" button on my view, a command gets executed that calls the private void Save() in my ViewModel.</p>
  
  <p>The problem is that the code in "Save()" takes some time to execute, so I'd like to hide the "Save" button in the UI view before executing the large chunk of code.</p>
  
  <p>The problem is that the view doesn't update untill all code is executed in the viewmodel.
  How can I force the view to redraw and process the PropertyChanged events before executing the Save() code?</p>
  
  <p>Additionally, I would like a reuseable way, so that I can easily do the same thing in other pages as well.. Anyone else made something like this already? A "Loading..." message?</p>