private void ListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.AddedItems.Count == 0)
{
return;
}
_selectedTop = e.AddedItems[0] as Top;
Top top = _selectedTop.Copy();
SetControlsVisibility(Visibility.Hidden);
if (_worker.IsBusy)
{
_worker.CancelAsync();
return;
}
_worker.RunWorkerAsync(top);
}