树型控件用来显示具有一定层次结构的数据项时方便、直观，被广泛地应用在各种软件中，如资源管理器中的磁盘目录就用的是树型

控件，我们在编程中也会经常用到，但 MFC 中提供的 CTreeCtrl 类并不直接支持拖动节点等高级特性，这使我们程序员编程时有很大限

制，又给软件用户带来了一些不便。下面就让我们自己动手来解决这个问题，实现树型控件中节点的拖动。

-tree control is used to indicate a certain level of the data structure when the convenient, intuitive, has been widely used in all kinds of software, such as resource management for the directory on disk using a tree control, We will be in programming frequently used. But the MFC CTreeCtrl category is not directly support drag nodes, and other senior properties This gives us programmers have strong programming restrictions, but also software users caused some inconvenience. Now let our own hands to solve the problem, realizing the tree control nodes Drive.