android 获取蓝牙已连接设备

蓝牙如果手动配对并已连接，获取连接的设备：

1.检测连接状态：

int a2dp = bluetoothAdapter.getProfileConnectionState(BluetoothProfile.A2DP);
                int headset = bluetoothAdapter.getProfileConnectionState(BluetoothProfile.HEADSET);
                int health = bluetoothAdapter.getProfileConnectionState(BluetoothProfile.HEALTH);

 2,根据是否有连接获取已连接的设备：

int flag = -1;
                if (a2dp == BluetoothProfile.STATE_CONNECTED) {
                    flag = a2dp;
                } else if (headset == BluetoothProfile.STATE_CONNECTED) {
                    flag = headset;
                } else if (health == BluetoothProfile.STATE_CONNECTED) {
                    flag = health;
                }

                if (flag != -1) {
                    bluetoothAdapter.getProfileProxy(MainActivity.this, new ServiceListener() {

                        @Override
                        public void onServiceDisconnected(int profile) {
                            // TODO Auto-generated method stub

                        }

                        @Override
                        public void onServiceConnected(int profile, BluetoothProfile proxy) {
                            // TODO Auto-generated method stub
                            List<BluetoothDevice> mDevices = proxy.getConnectedDevices();
                            if (mDevices != null && mDevices.size() > 0) {
                                for (BluetoothDevice device : mDevices) {
                                    Log.i("W", "device name: " + device.getName());
                                }
                            } else {
                                Log.i("W", "mDevices is null");
                            }
                        }
                    }, flag);
                }