In what way a WPF Wrap panel is slower that we need virtual wrap panel

Question

Hi,

I hear a lot about the wrap panel being slower to load things and hence we need a virtualising panel.

Can somebody give me a small wrap panel sample where it can be proven it is slower to load etc that it needs a virtualising panel please.

I set a wrap panel as a panel control for a listbox, and added 10000 string objects to it, and it was not a problem. I am sure my sample was silly, maybe i have to write a business object and create a larger data template to see this problem in action.

Kindly show me a sample that proves wrap panel without virtualisation is slower.

Thanks.

Answer 1

I think the performance issue depends mainly on the number of visual objects in your tree.

The default ListBoxItem template consists of a low number of elements (a border and a textblock i think). If you have a template that creates a complex visualization of lets say 100 visual elements per item you get a fairly large amount of visuals depending on your item count.

This is the reason why the normal panel is slower at load time, because it has to create all the objects at startup whereas the virtualising version only creates visuals for the visible items and disposes no longer displayed visuals.

In addition this has also implications on memory usage