title: What is the best way to detect if my page needs saving - ussing WPF MVVM
body: <p>I have an application where you can open many different items (like in excel you can open many different tabs) If an item or "tab" is modified I want to detect the changes and allow the use to save or prompt if the user closes without saving. Maybe enable/disabling save button when a save is available/not available.
  I am using c# WPF with MVVM pattern.</p>