MVVM- and Observable- Patterns are different Patterns and you will find many great examples. Assuming you are implementing a MVVM Phone App, these two patterns work great in combination:
- Your ViewModel (MVVM) has Properties which you want to display / update in your XAML-VIEW (MVVM).
Anytime you set (or update) a Property value (in your ViewModel) you trigger something like
()=> PropertyChanged("PropertyName);
- The Observer is now in your MVVM Framework (Or Base Class of ViewModel) this component observes these changes and manages the update with the VIEW.