Question

我有TrackingService组件，可根据众包来跟踪我所在城市的公交车位置。 TrackingService在后台运行，然后将数据传输到服务器。我有一个Map Activity来显示总线的位置，在MainActivity中选择的用户（作为Filter）。

应用程序启动时，后台TrackingService在MainActivity中启动。

我在BroadcastReceiver的帮助下通知map关于更新的lcoation的活动，如下面的代码所示。正在检索数据到地图活动，但我要解除注册bReceiver的问题。我想在应用程序进入后台或当用户按下后退按钮时取消注册广播，但我收到以下错误：

我该如何解决？

错误：

08-27 22:43:04.594: E/AndroidRuntime(19588): FATAL EXCEPTION: main
08-27 22:43:04.594: E/AndroidRuntime(19588): Process: com.bustracker, PID: 19588
08-27 22:43:04.594: E/AndroidRuntime(19588): java.lang.RuntimeException: Unable to stop activity {com.bustracker/com.bustracker.Map}: java.lang.IllegalArgumentException: Receiver not registered: com.bustracker.Map$1@2483d256
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:4156)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:4219)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread.access$1500(ActivityThread.java:177)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1502)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.os.Handler.dispatchMessage(Handler.java:102)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.os.Looper.loop(Looper.java:145)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread.main(ActivityThread.java:5944)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at java.lang.reflect.Method.invoke(Native Method)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at java.lang.reflect.Method.invoke(Method.java:372)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1389)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1184)
08-27 22:43:04.594: E/AndroidRuntime(19588): Caused by: java.lang.IllegalArgumentException: Receiver not registered: com.bustracker.Map$1@2483d256
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.LoadedApk.forgetReceiverDispatcher(LoadedApk.java:822)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ContextImpl.unregisterReceiver(ContextImpl.java:2038)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.content.ContextWrapper.unregisterReceiver(ContextWrapper.java:528)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at com.bustracker.Map.onStop(Map.java:418)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.Instrumentation.callActivityOnStop(Instrumentation.java:1275)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.Activity.performStop(Activity.java:6493)
08-27 22:43:04.594: E/AndroidRuntime(19588):    at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:4151)
08-27 22:43:04.594: E/AndroidRuntime(19588):    ... 10 more

TrackingService类：

public class TrackingService extends Service implements
        LocationListener {
    public double pLong;
    public double pLat;
    ...
        @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        detectLocation();
        return START_STICKY;
    }
    private void detectLocation() {
        lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30 * 1000, 0,
                this);
    }
    @Override
    public void onLocationChanged(Location location) {

        if (location != null) {
        pLong = location.getLongitude();
        pLat = location.getLatitude();

        Intent intent = new Intent(Map.RECEIVE_latLng);
        intent.putExtra("location",location);
        LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
           .....

     }  

}

地图活动：

    public class Map extends FragmentActivity implements OnMapReadyCallback   {
   public static final String RECEIVE_latLng = "com.bustracker.RECEIVE_latLng";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map);

    }
        @Override
protected void onStart() {
    super.onStart();        
    LocalBroadcastManager bManager =    LocalBroadcastManager.getInstance(this);
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction(RECEIVE_latLng);
    bManager.registerReceiver(bReceiver, intentFilter);
}

    private BroadcastReceiver bReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            if(intent.getAction().equals(RECEIVE_latLng)) {
                              Location location = intent.getParcelableExtra("location");
             double lng = location.getLongitude();
             double lat = location.getLatitude();
             LatLng ll = new LatLng(lat, lng);
             MarkerOptions markerOpt = new MarkerOptions().title("My Location")
                        .position(ll);
             System.out.println("ABC map: "+ lat + " ; " + lng);
             myLocatMarker = map.addMarker(markerOpt);
            }
          }
        };      
      }
@Override
protected void onStop() {
    super.onStop();
    unregisterReceiver(bReceiver);      
}

Answer 1

问题是如何注册和取消注册boradcast。所以我必须使用LocalBroadcastManager以这种方式取消注册：

@Override
protected void onStop() {
    super.onStop();
     LocalBroadcastManager.getInstance(this).unregisterReceiver(bReceiver);

}

LocalBroadcastManager - 未注册Receiver

1 个答案: