比如,鼠标移动到一个按钮上(pushbutton),则显示相关内容,如下图:
https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1550294590198&di=92b0962700eb5620886b6f21235b20bb&imgtype=jpg&src=http%3A%2F%2Fimg3.imgtn.bdimg.com%2Fit%2Fu%3D3680575353%2C534111438%26fm%3D214%26gp%3D0.jpg