1. 藍芽狀態是否連線:

    public static boolean isBTConnected(){
        BluetoothAdapter blueadapter = BluetoothAdapter.getDefaultAdapter();
//adapter也有getState(), 可獲取ON/OFF...其它狀態
        int a2dp = blueadapter.getProfileConnectionState(BluetoothProfile.A2DP);              //可操控藍芽裝置，如帶播放暫停功能的藍芽耳機
        int headset = blueadapter.getProfileConnectionState(BluetoothProfile.HEADSET);        //藍芽頭戴式耳機，支援語音輸入輸出
        int health = blueadapter.getProfileConnectionState(BluetoothProfile.HEALTH);
        return blueadapter != null && (a2dp == BluetoothAdapter.STATE_CONNECTED ||
                headset == BluetoothAdapter.STATE_CONNECTED ||
                health == BluetoothAdapter.STATE_CONNECTED);
    }
 

2. 藍芽變化監聽:

filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        filter.addAction(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED);
        //filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        registerReceiver(wifiReceiver, filter);


//onReceive:
else if(action.equals(BluetoothAdapter.ACTION_STATE_CHANGED)){
                int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,
                        BluetoothAdapter.ERROR);
                boolean enabled = (state == BluetoothAdapter.STATE_ON);
            }else if(action.equals(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED)){
                int status = intent.getIntExtra(BluetoothAdapter.EXTRA_CONNECTION_STATE,
                        BluetoothAdapter.STATE_DISCONNECTED);
                btConnected = (status == BluetoothAdapter.STATE_CONNECTED);
            }
 

感謝:

http://blog.csdn.net/memoryjs/article/details/42968823