CollectionViewSource is filtered?

What's the easiest way to know if the view is currently filtered or not? I want a clearAll type of command that is only is displayed when there is something to cl开发者_开发技巧ear.

Thanks!

Berryl

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The best way would be to compare the count of items in the View with the count of items in the source collection. If they are not the same, the view is filtered.