If your items are wider than the ListBox
, the other answers here won't help: the items in the ItemTemplate
remain wider than the ListBox
.
The fix that worked for me was to disable the horizontal scrollbar, which, apparently, also tells the container of all those items to remain only as wide as the list box.
Hence the combined fix to get ListBox items that are as wide as the list box, whether they are smaller and need stretching, or wider and need wrapping, is as follows:
<ListBox HorizontalContentAlignment="Stretch"
ScrollViewer.HorizontalScrollBarVisibility="Disabled">