It's telling you that longListSelector.ItemsSource
is of type IList
, but the value stored in selected
is an IEnumerable
, and you can't assign one to the other.
Try calling ToList()
:
var selected = (from c in myList
group c by c.MainTitle into n
select new GroupingLayer<string, MyObject>(n)).ToList();
longListSelector.ItemsSource = selected;