Tree Control 是最常见的Windows控件之一，建立有数据表接口的Tree Control对象，通过右键菜单完成Tree Control 节点的增删改等功能，Tree Control对象与ALV Grid对象的关联(Tree Control is one of the most common Windows controls, setting up Tree Control objects with a data table interface, completing and deletions of Tree Control nodes through the right key menu, and the association between Tree Control objects and ALV Grid objects)