This control mimics the behavior of Microsoft Outlook's categorized listbox. It displays a list of categories and each category has its own list of items. Categories can be opened to reveal their items or closed to hide them.
这个控件模仿了 Microsoft Outlook的分类列表框的功能。它可以显示许多分类,每个分类有自己的条目列表。可以打开分类,删除它们的条目,或关闭、隐藏它们。
来源: http://www.codeguru.com/listbox/CatListBox.html