带有VirtualizingStackPanel的WP7列表框中的选择性虚拟化

Question

I am referring an app like Facebook WP7 app. When we try to scroll a long list of the feed items. Only the heading of an feed item seems to be visible and when the scroll is completed remaining details gets loaded. If it is a normal Listbox where virtualization is enabled complete data disappears and all the controls seem to be recycled. So in facebook app, I thought that the virtualization is happening on selective items. Am I right?

If yes, how to do a selective virtualization? and if I am wrong what is the app exactly doing? Any resource regarding this will be helpful.

Thanks in advance.

Answer 1

As Willmell pointed out, this msdn link describes what Facebook is doing exactly. The template of the listBoxItem will be switched while scrolling.

Answer 2

Try to look here . This guide helps me to solve a similar problem.

Answer 3

I believe that this is just how their data binding works.

They get an initial list that contains the "headers" and some basic information, which they show. They then make more calls to grab the rest of the info. When that info comes in, it updates in the view model and thru databinding shows up on the list.

I have apps that do that, and they behave similarly to how FB's listbox behaves.