android常用的系统控件源码集，包括一些常用的界面控件的源码，比如菜单，单选按钮、按钮文字和背景的设置、带动画的按钮、按钮事件监听的实现、checkbox进行监听、EditText编辑框、单项选择、多项选择、Menu菜单、WebView使用等。- android common set of source code control systems, including some commonly used interface controls the source, such as men