private void List1_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (_dragged != null)
{
return;
}
UIElement element = List1.InputHitTest(e.GetPosition(List1)) as UIElement;
while (element != null)
{
if (element is ListBoxItem)
{
_dragged = (ListBoxItem)element;
break;
}
element = VisualTreeHelper.GetParent(element) as UIElement;
}
}