WPF Accordion VerticalAlignment bug

Question

Hi all,
Using the Accordion control from the latest WPF toolkit i came across this issue. When an accordion control has its VerticalAlignment set to 'Stretch' the AccordionItems contained within it will no longer expand if the SelectionMode is set to 'One'. If the selection mode is set to 'ZeroOrOne' you get expansion after several attempts at clicking. If it is set to 'ZeroOrMore' some really funky stuff happens where accordion items go missing off the bottom of the screen!

Anyone found a solution for this problem?

Thanks!

Answer 1

An OK workaround is to bind the ActualHeight and ActualWidth to the parent element you want it to fill. This is a bit of a hack but it will work.

Answer 2

You can also set the Accordion SelectionSequence property to CollapseBeforeExpand.

This bug is due to timing problems of the expanding/collapsing animation of each accordion item (when both expanding and collapsing happens simultaneously) with the layout update of the Accordion which messes up the size available for expansion.