Question

I use listbox.ScrollIntoView(item), but as long as this item is in listbox view, it won’t scroll.
Actually I want the item to be centered in the listbox’s view. Is there anyway to do this?

Answer 1

Unfortunately this is not all that easy, it depends on whether your listbox is virtualized or not, which depends on the panel that it uses to render its contents. For a non-virtualizing listbox, you can set the vertical scroll position by invoking the following method on the ScrollViewer which is part of the listbox template, where offset is in pixels.

ScrollViewer.ScrollToVerticalOffset(offset);

For virtualizing, you can invoke the following method on the VirtualizingStackPanel, where offset is the list location (you can use a double value, i.e. scrolling to 3.5 will scroll to half way between index 3 and 4):

ItemsHostStackPanel.SetVerticalOffset(offset);

For how to use this code in context, look at the jump list control I implemented here:

http://wp7contrib.codeplex.com/SourceControl/changeset/view/72741#1502048