vc++6.0 实现在视图/文档结构的应用程序中，用户可以将可拖动的窗口拖动到任何位置，也可以将它们停靠在窗口一边的功能。-vc++6.0 to achieve in the view/file structure of the application, the user can drag the window can be dragged to any location, you can also dock them to the s