Windows Store Apps quick tip: the sneaky selected item in CollectionViewSource

When assigning an ItemsSource there is a fundamental difference in CollectionViewSource vs “standard” collections: Using a CollectionViewSource will mark the first item as selected, using a “standard” collection will not.

Imagine if you will a ListView where you handle SelectionChanged and fetch data from somewhere depending on what item is selected. If you’re using a CollectionViewSource and navigate to the page you’ll fire that call twice – first for the default selected item, then for the passed in parameter that you’re likely using to the set SelectedItem.

That is all.