List Items Vertically on a WrapPanel and take advantage of multiple columns

I need to list items (all of same size) vertically (with a ScrollViewer). I want the items to spread through x columns if the container is large enough to display x columns I first tried that : ``` <ScrollViewer> <toolkit:WrapPanel Orientation="Horizontal" ItemHeight="30" ItemWidth="100"> <Button Content="1" /> <Button Content="2" /> <Button Content="3" /> <Button Content="4" /> <Button Content="5" /> </toolkit:WrapPanel> </ScrollViewer> ``` Result - The WrapPanel works like I want but my items are ordered from "Left to Right" (not vertically Then I tried to seet the Orientation of the WrapPanel to "Vertical" : Result - My items are ordered vertically but not spreaded on multiple columns. Here is how I'd like items to be rendered : I'd really like to avoid having to write code monitoring the control size to create/remove columns depending on its size.