Object Model

Base classes are included for implementing observable and disposable objects.

Observable Objects

The abstract ObservableObjectBase class implements both the INotifyPropertyChanging and INotifyPropertyChanged interfaces. These interfaces allow objects inheriting the base class to publish property change notifications.

Setting Property Values

Classes inheriting ObservableObjectBase should invoke the protected SetProperty method from property setters. This method is passed:

• The backing field (by-reference) to update that holds the property value.
• The new value.
• The optional name of the property being updated, if different from the caller property.

The OnPropertyChanging method is called immediately before a property's backing field is updated. The default implementation of that method raises the PropertyChanging event.

Similarly, the OnPropertyChanged method is called immediately after a property's backing field is updated. The default implementation of that method raises the PropertyChanged event.

Inheriting the Base Class

The following example shows how to create an observable object by inheriting the ObservableObjectBase class:

public class ViewModel : ObservableObjectBase {

	private bool? _isActive;

	public bool? IsActive {
		get => _isActive;
		set => SetProperty(ref _isActive, value);
	}

}

Disposable Objects

The abstract DisposableObjectBase class implements the IDisposable interface and the disposable object pattern.

The base class has a finalizer that calls a protected abstract Dispose method overload. Its implementation of the IDisposable interface's public Dispose method also calls into the protected abstract Dispose method overload and suppresses finalization.

Inheriting the Base Class

The following example shows how to create a disposable object by inheriting the DisposableObjectBase class and overriding the protected Dispose method:

public class MyDisposableObject : DisposableObjectBase {

	protected override void Dispose(bool disposing) {
		if (disposing) {
			// Free any managed objects here
		}

		// Free any unmanaged objects here
	}

}