VB窗体前置实例，让窗口显示在其它打开窗口的上方，不被其它应用程序的窗口所遮挡，常见于一些视频播放器中，在播放视频时显示在最前端，边工作边看视频。-VB form on the top case, let the window above the other open windows, not by other application program window shade, common in some video player, display in the front when play