public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var parentItemsControl = VisualTreeHelpers.FindAncestorOrSelf <ItemsControl>(container);
if ((item != null) && (parentItemsControl != null))
{
var items = parentItemsControl.Items;
if (items.IsEmpty)
{
return(null);
}
// if only one element is present
if (items.Count == 1)
{
return(SingleElementTemplate);
}
var index = items.IndexOf(item);
// if first item
if (index == 0)
{
return(FirstElementTemplate);
}
// if last item
if (!items.IsEmpty && (index == items.Count - 1))
{
return(LastElementTemplate);
}
return(MiddleElementTemplate);
}
return(null);
}