安卓设备如何监听蓝牙的连接状态

Question

如题，在我的APP中，成功将手机连接上了一个蓝牙串口，现在想监听它们之间的连接状态。在网上找到的方式都是用BroadcastReceiver来监听蓝牙状态改变的广播，于是我实现了这种方式，代码部分如下：
    private void registerBoradcastReceiver() {
    IntentFilter stateChangeFilter = new IntentFilter(
            BluetoothAdapter.ACTION_STATE_CHANGED);
    IntentFilter connectedFilter = new IntentFilter(
            BluetoothDevice.ACTION_ACL_CONNECTED);
    IntentFilter disConnectedFilter = new IntentFilter(
            BluetoothDevice.ACTION_ACL_DISCONNECTED);
    registerReceiver(stateChangeReceiver, stateChangeFilter);
    registerReceiver(stateChangeReceiver, connectedFilter);
    registerReceiver(stateChangeReceiver, disConnectedFilter);
}

    private BroadcastReceiver stateChangeReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (BluetoothDevice.ACTION_ACL_CONNECTED == action) {
            showchange(action);
        }
        if (BluetoothDevice.ACTION_ACL_DISCONNECTED == action) {
            showchange(action);
        }
        if (BluetoothAdapter.ACTION_STATE_CHANGED == action) {
            showchange(action);
        }
    }
};

但是调试的时候并没有监听到任何的状态变化，求指教。

Answer 1

将IntentFilter connectedFilter = new IntentFilter(
BluetoothDevice.ACTION_ACL_CONNECTED);
换成IntentFilter connectedFilter = new IntentFilter(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED);再试下
同时，注意加上蓝牙的相关权限