public static UIElement GetClosestItemContainerToPosition(ItemsControl itemsControl, Point point, Orientation orientation)
{
Type itemContainerType = ControlMethods.GetItemContainerType(itemsControl);
if (itemContainerType == null)
{
return(null);
}
List <UIElement> containers = new List <UIElement>();
LineGeometry line;
switch (orientation)
{
case Orientation.Horizontal:
line = new LineGeometry(new Point(0d, point.Y), new Point(itemsControl.RenderSize.Width, point.Y));
break;
default:
line = new LineGeometry(new Point(point.X, 0d), new Point(point.X, itemsControl.RenderSize.Height));
break;
}
line.Freeze();
VisualTreeHelper.HitTest(
itemsControl,
null,
testResult =>
{
UIElement itemContainer = testResult.VisualHit.FindVisualTreeAncestor(itemContainerType) as UIElement;
if (itemContainer != null && itemsControl.Equals(ItemsControl.ItemsControlFromItemContainer(itemContainer)))
{
containers.Add(itemContainer);
}
return(HitTestResultBehavior.Continue);
},
new GeometryHitTestParameters(line)
);
switch (containers.Count)
{
case 0:
return(null);
case 1:
return(containers[0]);
}
// Find closest item to the point clicked.
UIElement closest = null;
double closestDistance = double.MaxValue;
foreach (UIElement container in containers)
{
Point transform = container.TransformToAncestor(itemsControl).Transform(default(Point));
double distance = Math.Abs(orientation == Orientation.Horizontal ? point.X - transform.X : point.Y - transform.Y);
if (distance < closestDistance)
{
closest = container;
closestDistance = distance;
}
}
return(closest);
}
public static UIElement GetItemContainer(this ItemsControl itemsControl, UIElement child)
{
Type itemContainerType = ControlMethods.GetItemContainerType(itemsControl);
if (itemContainerType == null)
{
return(null);
}
for (UIElement element = VisualTreeHelper.GetParent(child) as UIElement; element != null && !itemsControl.Equals(element); element = VisualTreeHelper.GetParent(element) as UIElement)
{
if (itemContainerType.IsInstanceOfType(element) && itemsControl.Equals(ItemsControl.ItemsControlFromItemContainer(element)))
{
return(element);
}
}
return(null);
}