Xamarin.Forms for WPF Not able to clear ListView selection

Hi,

Description:
Create a ListView
Assign a ObservableCollection object to Listview.ItemSource
The collection is displayed on the ListView

experiment 1:
-I change the ListView elements by reassigning a different collection to Listview.ItemSoure. This works fine.
-If I change the collection elements, it gets updated in the ListView. This also works fine.

But,

experiment 2:
-Select an item in ListView.
-After selection, when I try to change the collection (either observable or changing ItemsSource), NotImplementedException being thrown here.

I'm not able to clear the selectedItem in ListView and also not able to update the ListView after an item is selected in the ListView.

Please suggest a solution for this.

Thanks,
Chand