wpf - INotifyPropertyChanged vs. DependencyProperty in ViewModel

Question

When implementing the ViewModel in a Model-View-ViewModel architecture WPF application there seem to be two major choices how to make it databindable. I have seen implementations that use DependencyProperty for properties the View is going to bind against and I have seen the ViewModel implementing INotifyPropertyChanged instead.

My question is when should I prefer one over the other? Are there any performance differences? Is it really a good idea to give the ViewModel dependencies to WPF? What else do I need to consider when make the design decision?

Answer 1

Kent wrote an interesting blog about this topic: View Models: POCOs versus DependencyObjects.

Short summary:

1. DependencyObjects are not marked as serializable
2. The DependencyObject class overrides and seals the Equals() and GetHashCode() methods
3. A DependencyObject has thread affinity – it can only be accessed on the thread on which it was created

I prefer the POCO approach. A base class for PresentationModel (aka ViewModel) which implements INotifyPropertyChanged interface can be found here: http://compositeextensions.codeplex.com