/// <summary>
/// Called when the <see cref="Behavior{T}"/> is about to detach from the
/// <see cref="Behavior{T}.AssociatedObject"/>.
/// </summary>
/// <remarks>
/// When this method is called, detaching can not be canceled. The
/// <see cref="Behavior{T}.AssociatedObject"/> is still set.
/// </remarks>
protected override void OnDetaching()
{
if (_propertyObserver != null)
{
_propertyObserver.Dispose();
_propertyObserver = null;
}
base.OnDetaching();
}
//--------------------------------------------------------------
/// <summary>
/// Initializes a new instance of the <see cref="ReflectedProperty"/> class.
/// </summary>
/// <param name="instance">The object instance.</param>
/// <param name="property">The property.</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="instance"/> or <paramref name="property"/> is <see langword="null"/>.
/// </exception>
public ReflectedProperty(object instance, PropertyDescriptor property)
{
if (instance == null)
throw new ArgumentNullException(nameof(instance));
if (property == null)
throw new ArgumentNullException(nameof(property));
Instance = instance;
Descriptor = property;
_bindablePropertyObserver = new BindablePropertyObserver(instance, property.Name);
_bindablePropertyObserver.ValueChanged += OnValueChanged;
}
/// <summary>
/// Called after the behavior is attached to an <see cref="Behavior{T}.AssociatedObject"/>.
/// </summary>
/// <remarks>
/// Override this to hook up functionality to the
/// <see cref="Behavior{T}.AssociatedObject"/>.
/// </remarks>
protected override void OnAttached()
{
base.OnAttached();
var commandSource = AssociatedObject as ICommandSource;
if (commandSource == null)
{
return;
}
_propertyObserver = new BindablePropertyObserver(AssociatedObject, "CommandParameter");
_propertyObserver.ValueChanged += OnCommandParameterChanged;
}
//--------------------------------------------------------------
#region Creation & Cleanup
//--------------------------------------------------------------
/// <summary>
/// Initializes a new instance of the <see cref="ReflectedProperty"/> class.
/// </summary>
/// <param name="instance">The object instance.</param>
/// <param name="property">The property.</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="instance"/> or <paramref name="property"/> is <see langword="null"/>.
/// </exception>
public ReflectedProperty(object instance, PropertyDescriptor property)
{
if (instance == null)
{
throw new ArgumentNullException(nameof(instance));
}
if (property == null)
{
throw new ArgumentNullException(nameof(property));
}
Instance = instance;
Descriptor = property;
_bindablePropertyObserver = new BindablePropertyObserver(instance, property.Name);
_bindablePropertyObserver.ValueChanged += OnValueChanged;
}
public void GarbageCollection()
{
var source = new Slider();
//var source = new Foo();
var sourceWeak = new WeakReference(source);
var observer = new Foo();
var observerWeak = new WeakReference(observer);
var bpo = new BindablePropertyObserver(source, "Value");
bpo.ValueChanged += observer.OnObservedValueChanged;
//var pd = TypeDescriptor.GetProperties(typeof(Foo)).OfType<PropertyDescriptor>().First(d => d.Name == "Value");
//pd.AddValueChanged(source, observer.OnObservedValueChanged);
Assert.That(observer.Value, Is.EqualTo(0));
source.Value = 1;
Assert.That(observer.Value, Is.EqualTo(1));
source.Value = 2;
Assert.That(observer.Value, Is.EqualTo(2));
Assert.IsTrue(sourceWeak.IsAlive);
Assert.IsTrue(observerWeak.IsAlive);
source = null;
GC.Collect();
Assert.IsFalse(sourceWeak.IsAlive); // This works for DependencyObjects but not for normal CLR objects with INotifyPropertyChanged;
Assert.IsTrue(observerWeak.IsAlive);
observer = null;
bpo = null;
GC.Collect();
Assert.IsFalse(sourceWeak.IsAlive);
Assert.IsFalse(observerWeak.IsAlive);
}
public void GarbageCollection()
{
var source = new Slider();
//var source = new Foo();
var sourceWeak = new WeakReference(source);
var observer = new Foo();
var observerWeak = new WeakReference(observer);
var bpo = new BindablePropertyObserver(source, "Value");
bpo.ValueChanged += observer.OnObservedValueChanged;
//var pd = TypeDescriptor.GetProperties(typeof(Foo)).OfType<PropertyDescriptor>().First(d => d.Name == "Value");
//pd.AddValueChanged(source, observer.OnObservedValueChanged);
Assert.That(observer.Value, Is.EqualTo(0));
source.Value = 1;
Assert.That(observer.Value, Is.EqualTo(1));
source.Value = 2;
Assert.That(observer.Value, Is.EqualTo(2));
Assert.IsTrue(sourceWeak.IsAlive);
Assert.IsTrue(observerWeak.IsAlive);
source = null;
GC.Collect();
Assert.IsFalse(sourceWeak.IsAlive); // This works for DependencyObjects but not for normal CLR objects with INotifyPropertyChanged;
Assert.IsTrue(observerWeak.IsAlive);
observer = null;
bpo = null;
GC.Collect();
Assert.IsFalse(sourceWeak.IsAlive);
Assert.IsFalse(observerWeak.IsAlive);
}