/// <summary>
/// Detaches the listener.
/// </summary>
public void Detach()
{
if (RelayInstance == null)
return;
var temp = RelayInstance;
RelayInstance = null;
temp.ClearValue(RelayObject.ValueProperty);
}
/// <summary>
/// Creates a new instance of <see cref="DependencyPropertyChangedListener" />.
/// </summary>
/// <param name="sourceElement">The source element.</param>
/// <param name="propertyPath">The property path.</param>
/// <returns>The <see cref="DependencyPropertyChangedListener" />.</returns>
/// <exception cref="System.ArgumentNullException">sourceElement</exception>
/// <exception cref="System.ArgumentException">propertyPath is empty.</exception>
/// <exception cref="ArgumentNullException">The <paramref name="sourceElement" /> parameter is null.</exception>
/// <exception cref="ArgumentException">The <paramref name="propertyPath" /> is null or whitespace.</exception>
public static DependencyPropertyChangedListener Create(DependencyObject sourceElement, string propertyPath)
{
if (sourceElement == null)
throw new ArgumentNullException("sourceElement");
if (string.IsNullOrWhiteSpace(propertyPath))
throw new ArgumentException("propertyPath is empty.");
var listener = new DependencyPropertyChangedListener();
var binding = new Binding(propertyPath) { Source = sourceElement, Mode = BindingMode.OneWay };
var relay = new RelayObject(listener);
listener.RelayInstance = relay;
BindingOperations.SetBinding(relay, RelayObject.ValueProperty, binding);
return listener;
}
