Revalidate all RadGridView

[jocker none]

Hi, some questions for you:
1) How i can revalidate all rows in RadGridView (how to iterate and validate row) ?
2) If i add new data to IObservable<T> (my custom data context), how i can set added row to edit mode?
This code can't do this:

gridView.RowLoaded += new EventHandler<RowLoadedEventArgs>(gridView_RowLoaded);
...
void OrderPackGridView_RowLoaded(object sender, RowLoadedEventArgs e)
{
                e.Row.IsSelected = true;
                (sender as RadGridView).BeginEdit();
}

(it set selection, but not edit area to added row)

Thanks.