public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (!(value is ListBoxItem))
{
throw new ArgumentException("value is not ListBoxItem.");
}
ListBoxItem listBoxItem = (ListBoxItem)value;
ListBox listBox = listBoxItem.FindAncestor <ListBox>();
if (listBox == null)
{
return(0);
}
return(listBox.ItemContainerGenerator.IndexFromContainer(listBoxItem) + 1);
}
