说明：  AppWidget_Android开发中惯用的窗口小部件（App Widgets）的使用教程，App Widgets在Android开发中也叫做应用程序窗口小部件，可以被嵌入到其它应用程序中（比如桌面）并接收周期性的更新。
(AppWidget_Tutorial for using widgets (App Widgets) commonly used in Android development. App Widgets are also called application widgets in Android development and can be embedded in other applications (such as desktop) and receive periodic updates.)