My prototype displays "documents" that contain "pages" that are
represented by thumbnail images. Each document can have
any number of pages. For example, there might be
1000 documents with 5 pages each, or 5 documents with 1000 pages
each, or somewhere inbetween. Documents do not contain other documents.
In my xaml markup I have a ListBox, whose ItemsTemplate
references an innerItemsTemplate that also has a ListBox. I want the
2 levels of selected items so that I can perform various operations
on documents or pages (delete, merge, move to new location, etc).
The innerItemsTemplate ListBox uses a WrapPanel as the ItemsPanelTemplate.
For the scenario where I have a large number of documents with a few
pages each (say, 10000 documents with 5 pages each), the scrolling
works great thanks to the UI Virtualization by the VirtualizingStackPanel.
However, I have problems if I have a large number of pages. A document
with 1000 pages will only display about 50 at a time (whatever fits on the screen), and when I scroll down, the outer ListBox moves to the next document, skipping the 950
pages or so that were not visible. Along with that, there is no
VirtualzingWrapPanel so the app memory really increases.
I'm wondering if I am going about this the right way, especially since it is sort of difficult to explain! I would like to be able to display 10000 documents with 1000 pages each (only showing whatever fits on the screen), using UI Virtualization, and also smooth scrolling.
How can I make sure the scrolling moves through all of the pages in document before it displays the next document, and still keep UI virtualization? The scrollbar seems to only move to the next document.
Does it seem logical to represent "documents" and "pages" -
with my current method of using a ListBox within a ListBox?