The dirty state of an entity is monitored by the data context. This is usually accomplished with change notifications, provided through the
INotifyPropertyChanged.PropertyChanged events, raised in the property setters of the entity.
PropertyChanging events raising into every property setter can add up to a lot of plumbing code. Fortunately the
Assign method, in the custom
ViewModelBase class, used throughout this book, raises the events required for change tracking.
For more information on the property change notification, in relation to the
ViewModelBase class, see Chapter 2.
For entities that do not implement