/// <summary>
/// Converts selectedItems to string ISBNs.
/// </summary>
/// <param name="selectedItems"></param>
/// <param name="books"></param>
/// <returns>List<Book></returns>
private List <Book> GetSelectedItems(ListBox.
SelectedObjectCollection selectedItems)
{
List <string> stringISBNs = new List <string>();
foreach (var item in selectedItems)
{
stringISBNs.Add(item.ToString().
Substring(0, item.ToString().IndexOf(",")));
}
List <Book> selectedBooks =
LibraryDB.GetSelectedBooks(stringISBNs);
return(selectedBooks);
}
