这是一个基于android系统的wifi工具类，它包含了打开关闭wifi，获取wifi信息以及切换到指定wifi等方法，并实现了对wifi连接状态的监听，它可以满足绝大多数wifi开发需求。(This is a WiFi Tool for Android, which includes open and close WiFi, WiFi access to information and switch to the specified WiFi, and realized the connect

Android源码 3G和wifi的切换监听(Android source code, 3G and WiFi switching monitor)