Dependency Property

private static DependencyProperty RegisterProperty<T>(
    Expression<Func<BindableListBox, T>> associatedProperty,
    T defaultValue,
    Action<BindableListBox> valueChangedAction = null)
{
    return DependencyProperty.Register(
        GetPropertyName(associatedProperty),
        typeof(T),
        typeof(BindableListBox),
        new PropertyMetadata(defaultValue, (s, e) =>
        {
            var sender = s as BindableListBox;
            if (sender != null)
            {
                valueChangedAction?.Invoke(sender);
            }
        }));
}