说明：  安卓环境下的悬浮Log窗口。基于Service启动。有别于一般悬浮窗的是可在屏幕上进行拖动，并且Log窗口可实现滚动功能，借此架构可是实现各类可拖动的悬浮窗。
(Android Log window. Based Service starts. Unlike ordinary floating window that can be dragged on the screen and Log window enables scrolling function)