TreeViewItem.Items.RemoveAll() in condition

[Kelley Wong]

The treeview is showed as follows:
-School           (School Class)
   -Teacher  A          (Teacher Class)
   -Teacher  B
   -Class A         (Class Class)
       -Jim                (Student Class)
       -Tom
       -Tim
   -Class B
   -Class C

i right click on the Root Note(School) ,it shows a contextmenu to refresh the Teachers
so I want to  use TreeViewItem.Items.RemoveAll(Predicate ) to remove the Teachers on the treeview first
but how to use ItemCollection.RemoveAll(Predicate )

[Petar Mladenov]

Hello Kelley Wong,

You cannot filter with Predicate the way you want in Silverlight. If your tree is databound to ObservableCollection, you can filter the source collection and rebind the tree like so:

ObservableCollection<DataItem> col = new ObservableCollection<DataItem>();
            col = new ObservableCollection<string>()(col.Where(x => x.Names.StartsWith("abc")));
            tree.ItemsSource = col;

If your tree is declarative or created from code behind, you have to iterate over the Items collection and use the Remove method if the RadTreeViewitems meets your condition.

Greetings,
Petar Mladenov
the Telerik team