scrollviewer fix

    public class BubbleMouseWheelEvents : AttachableForStyleBehavior<UIElement, BubbleMouseWheelEvents>
    {
        protected override void OnAttached()
        {
            AssociatedObject.PreviewMouseWheel += PreviewMouseWheel;
        }

        protected override void OnDetaching()
        {
            AssociatedObject.PreviewMouseWheel -= PreviewMouseWheel;
        }

        private void PreviewMouseWheel(object sender, MouseWheelEventArgs e)
        {
            var scrollViewer = AssociatedObject.GetChildOf<ScrollViewer>(includeSelf: true);
            var scrollPos = scrollViewer.ContentVerticalOffset;
            if ((scrollPos == scrollViewer.ScrollableHeight && e.Delta < 0) || (scrollPos == 0 && e.Delta > 0))
            {
                UIElement rerouteTo = AssociatedObject;
                if (ReferenceEquals(scrollViewer, AssociatedObject))
                {
                    rerouteTo = (UIElement)VisualTreeHelper.GetParent(AssociatedObject);
                }

                e.Handled = true;
                var e2 = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta);
                e2.RoutedEvent = UIElement.MouseWheelEvent;
                rerouteTo.RaiseEvent(e2);
            }
        }
    }

    public class AttachableForStyleBehavior<TComponent, TBehavior> : Behavior<TComponent>
        where TComponent : System.Windows.DependencyObject
        where TBehavior : AttachableForStyleBehavior<TComponent, TBehavior>, new()
    {
        public static DependencyProperty IsEnabledForStyleProperty =
            DependencyProperty.RegisterAttached("IsEnabledForStyle", typeof(bool),
                                                typeof(AttachableForStyleBehavior<TComponent, TBehavior>), new FrameworkPropertyMetadata(false, OnIsEnabledForStyleChanged));

        public bool IsEnabledForStyle
        {
            get { return (bool)GetValue(IsEnabledForStyleProperty); }
            set { SetValue(IsEnabledForStyleProperty, value); }
        }

        private static void OnIsEnabledForStyleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            UIElement uie = d as UIElement;

            if (uie != null)
            {
                var behColl = Interaction.GetBehaviors(uie);
                var existingBehavior = behColl.FirstOrDefault(b => b.GetType() ==
                                                                   typeof(TBehavior)) as TBehavior;

                if ((bool)e.NewValue == false && existingBehavior != null)
                {
                    behColl.Remove(existingBehavior);
                }

                else if ((bool)e.NewValue == true && existingBehavior == null)
                {
                    behColl.Add(new TBehavior());
                }
            }
        }
    }