http://stackoverflow.com/questions/4715865/how-to-programmatically-tell-if-a-bluetooth-device-is-connected-android-2-2
How to programmatically tell if a Bluetooth device is connected? (Android 2.2),布布扣,bubuko.com
How to programmatically tell if a Bluetooth device is connected? (Android 2.2)
原文：http://www.cnblogs.com/yanyongcong/p/3577375.html
