对于界面重绘的一个集合库，包括菜单，按扭，进度条，等等，类似于一个mfc的扩展，所以取名叫mfc_ex.dll,-Redraw the interface of a collection of libraries, including the menus, buttons, progress bar, and so on, similar to a mfc extension, so check the name of mfc_ex.dll,