public void Bind(ExtendedListBox list)
{
listbox = list;
listbox.LayoutUpdated += OnLayoutUpdate;
scrollViewer = listbox.Descendants().OfType <ScrollViewer>().FirstOrDefault();
scrollOffsetMargin = 0.5 * scrollViewer.ViewportHeight;
Bound = true;
}
public void Bind(ExtendedListBox listbox)
{
lb = listbox;
Deployment.Current.Dispatcher.InvokeIfRequired(() => {
scrollViewer = listbox.Descendants().OfType <ScrollViewer>().FirstOrDefault();
lb.ManipulationCompleted += lb_ManipulationCompleted;
});
Bound = true;
}
public void Bind(ExtendedListBox listbox)
{
lb = listbox;
scrollViewer = lb.Descendants().OfType <ScrollViewer>().FirstOrDefault();
if (scrollViewer == null)
{
throw new NotSupportedException("ExtendedListbox must have an underlying ScrollViewer");
}
lb.ManipulationCompleted += lb_ManipulationCompleted;
Bound = true;
}
private ITweetable GetFirstVisibleItem()
{
var items = lb.ViewportItems;
if (items.Count == 0)
{
return(null);
}
var offset = lb.Descendants().OfType <ViewportControl>().FirstOrDefault().Viewport.Top;
var visibleItems = items.Where(x => Canvas.GetTop(x.Value) + x.Value.ActualHeight > offset)
.OrderBy(x => Canvas.GetTop(x.Value));
if (visibleItems.Any())
{
return(visibleItems.First().Key);
}
else
{
return(null);
}
}