Question

我正在尝试发现蓝牙设备，出于某种原因，我一直得到接收器从未注册的非法例外。

我之前能够在Fragment上发现设备。这使得UI等待发现过程在它执行任何操作之前完成，因此我尝试将此代码移动到AsyncTask。同样的问题。我不确定我哪里出错了。欢迎任何帮助/建议。

public class HomeFragment extends Fragment{

private View rootView;
private ToggleButton toggleButton;
private TextView lockStatus;
private TextView connectionToLock;
private ArrayList<BluetoothDevice> availableDevices;
private BluetoothAdapter bluetoothAdapter;


public HomeFragment(){};

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    rootView = inflater.inflate(R.layout.fragment_home, container, false);
    toggleButton = (ToggleButton) rootView.findViewById(R.id.toggleLock);
    lockStatus = (TextView) rootView.findViewById(R.id.lockStatus);
    connectionToLock = (TextView)rootView.findViewById(R.id.connectionToLock);
    availableDevices = new ArrayList<BluetoothDevice>();

    lockStatus.setText("Lock Status: DEFAULT");
    connectionToLock.setText("Searching for BT Devices ...");

    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    btDeviceDiscovery();
    return rootView;
}

private void btDeviceDiscovery(){
    //assume bt is turned on for now
    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    filter.addAction(BluetoothDevice.ACTION_UUID);
    filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
    filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

    getActivity().getApplicationContext().registerReceiver(ActionFoundReceiver, filter);
    Log.i("BT Discovery", "Devices found: "+availableDevices.size());
}

@Override
public void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    try {
        getActivity().unregisterReceiver(ActionFoundReceiver);
    } catch (Exception e) {
        Log.i("onDestroy", e.toString());
        e.printStackTrace();
    }
}

private final BroadcastReceiver ActionFoundReceiver = new BroadcastReceiver(){

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.i("onReceive", "Finally Called");
        String action = intent.getAction();
        connectionToLock.setText("Found Devices :- \n");

        if(BluetoothDevice.ACTION_FOUND.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            Log.i("onReceive", "\n  Device: " + device.getName() + ", " + device);
            availableDevices.add(device);
            connectionToLock.append(device.getName()+ " \n");
        } else {
            connectionToLock.setText("No Bluetooth Devices in range.");
        }

    }

};

}

堆栈跟踪：

02-05 15:17:45.227: W/System.err(11086): java.lang.IllegalArgumentException: Receiver not registered: com.naftal.easylock.ui.fragment.HomeFragment$1@4259a7b8
02-05 15:17:45.227: W/System.err(11086):    at android.app.LoadedApk.forgetReceiverDispatcher(LoadedApk.java:667)
02-05 15:17:45.227: W/System.err(11086):    at android.app.ContextImpl.unregisterReceiver(ContextImpl.java:1743)
02-05 15:17:45.227: W/System.err(11086):    at android.content.ContextWrapper.unregisterReceiver(ContextWrapper.java:475)
02-05 15:17:45.227: W/System.err(11086):    at com.naftal.easylock.ui.fragment.HomeFragment.onDestroy(HomeFragment.java:69)
02-05 15:17:45.227: W/System.err(11086):    at android.app.Fragment.performDestroy(Fragment.java:1908)
02-05 15:17:45.237: W/System.err(11086):    at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1026)
02-05 15:17:45.237: W/System.err(11086):    at android.app.FragmentManagerImpl.removeFragment(FragmentManager.java:1180)
02-05 15:17:45.237: W/System.err(11086):    at android.app.BackStackRecord.run(BackStackRecord.java:639)
02-05 15:17:45.237: W/System.err(11086):    at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1455)
02-05 15:17:45.237: W/System.err(11086):    at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
02-05 15:17:45.237: W/System.err(11086):    at android.os.Handler.handleCallback(Handler.java:730)
02-05 15:17:45.237: W/System.err(11086):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-05 15:17:45.237: W/System.err(11086):    at android.os.Looper.loop(Looper.java:137)
02-05 15:17:45.237: W/System.err(11086):    at android.app.ActivityThread.main(ActivityThread.java:5455)
02-05 15:17:45.237: W/System.err(11086):    at java.lang.reflect.Method.invokeNative(Native Method)
02-05 15:17:45.237: W/System.err(11086):    at java.lang.reflect.Method.invoke(Method.java:525)
02-05 15:17:45.237: W/System.err(11086):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
02-05 15:17:45.237: W/System.err(11086):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
02-05 15:17:45.247: W/System.err(11086):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

我的猜测是，您在Intent注册之前收到了BroadcastReceiver。你调用一个注册接收器的方法，但是在它到达注册过程的那段时间内，接收器可能会收到Intent，但它还没有注册。

----编辑----

还有另外一个想法：当你注册接收者之前，你可能会在unregisterReceiver()未注册时调用onDestroy()，或者基本上在调用registerReceiver()方法时调用{{1}}方法。所以它可以基于处理你的Fragment，在它被销毁时尝试调试，然后调试你是否在此之前调用了{{1}}。

Answer 2

尝试在你的onCreate（）方法中注册它，如下所示：

@Override
public void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getActivity().getApplicationContext().registerReceiver(ActionFoundReceiver, filter);
}

如果广播仅在您的应用中使用，则应使用LocalBoradcastManager，因为这些广播不会离开您的应用。

希望这会有所帮助。

BroadcastReceiver未设置

2 个答案: