从android react-native RCTDeviceEventEmitter向JavaScript发送事件

Question

我正在尝试在位置更新时从Android端收到一个事件。这是我的代码：

package com.prop;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.location.Location;
import android.support.v4.content.LocalBroadcastManager;

import com.facebook.react.bridge.Arguments;
import com.facebook.react.bridge.Promise;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import com.facebook.react.bridge.WritableMap;
import com.facebook.react.modules.core.DeviceEventManagerModule;

public class GeoLocationModule extends ReactContextBaseJavaModule {
    public GeoLocationModule(final ReactApplicationContext reactContext) {
        super(reactContext);
        BroadcastReceiver geoLocationReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                Location message = intent.getParcelableExtra("message");
                WritableMap map = Arguments.createMap();
                WritableMap coordMap = Arguments.createMap();
                coordMap.putDouble("latitude", message.getLatitude());
                coordMap.putDouble("longitude", message.getLongitude());
                coordMap.putDouble("accuracy", message.getAccuracy());
                coordMap.putDouble("altitude", message.getAltitude());
                coordMap.putDouble("heading", message.getBearing());
                coordMap.putDouble("speed", message.getSpeed());

                map.putMap("coords", coordMap);
                map.putDouble("timestamp", message.getTime());

                reactContext
                .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
                .emit("updateLocation", map);

            }
        };
        LocalBroadcastManager.getInstance(getReactApplicationContext()).registerReceiver(geoLocationReceiver, new IntentFilter("GeoLocationUpdate"));
    }

    @Override
    public String getName() {
        return "GeoLocation";
    }

    @ReactMethod
    public void startService(Promise promise) {
        String result = "Success";
        try {
            Intent intent = new Intent(GeoLocationService.FOREGROUND);
            intent.setClass(this.getReactApplicationContext(), GeoLocationService.class);
            getReactApplicationContext().startService(intent);
        } catch (Exception e) {
            promise.reject(e);
            return;
        }
        promise.resolve(result);
    }

    @ReactMethod
    public void stopService(Promise promise) {
        String result = "Success";
        try {
            Intent intent = new Intent(GeoLocationService.FOREGROUND);
            intent.setClass(this.getReactApplicationContext(), GeoLocationService.class);
            this.getReactApplicationContext().stopService(intent);
        } catch (Exception e) {
            promise.reject(e);
            return;
        }
        promise.resolve(result);
    }

    private void sendEvent(Location message) {
        WritableMap map = Arguments.createMap();
        WritableMap coordMap = Arguments.createMap();
        coordMap.putDouble("latitude", message.getLatitude());
        coordMap.putDouble("longitude", message.getLongitude());
        coordMap.putDouble("accuracy", message.getAccuracy());
        coordMap.putDouble("altitude", message.getAltitude());
        coordMap.putDouble("heading", message.getBearing());
        coordMap.putDouble("speed", message.getSpeed());

        map.putMap("coords", coordMap);
        map.putDouble("timestamp", message.getTime());

        getReactApplicationContext().getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class).emit("updateLocation", map);
    }
}

并且在React本机端 DeviceEventEmitter 就像：

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from 'react';
import {
  Platform,
  StyleSheet,
  Text,
  View,
  DeviceEventEmitter
} from 'react-native';

const instructions = Platform.select({
  ios: 'Press Cmd+R to reload,\n' +
    'Cmd+D or shake for dev menu',
  android: 'Double tap R on your keyboard to reload,\n' +
    'Shake or press menu button for dev menu',
});

const updateLocation = (geoData) => {
  alert(geoData)
};

DeviceEventEmitter.addListener('onSessionConnect', updateLocation);

type Props = {};
export default class App extends Component<Props> {
  componentWillMount() {
    alert('test');
    DeviceEventEmitter.addListener('updateLocation', function (geoData) {
      // handle event.
      alert(geoData);
    });
  }

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started, edit App.js
        </Text>
        <Text style={styles.instructions}>
          {instructions}
        </Text>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});

我无法弄清楚为什么它不会触发位置更新我的服务类是：

package com.prop;

import android.annotation.TargetApi;
import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.BitmapFactory;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Build;
import android.os.Bundle;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.support.v4.app.NotificationCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.LocalBroadcastManager;
import android.R;

public class GeoLocationService extends Service {
    public static final String FOREGROUND = "com.prop.location.FOREGROUND";
    private static int GEOLOCATION_NOTIFICATION_ID = 12345689;
    LocationManager locationManager = null;
    LocationListener locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
            GeoLocationService.this.sendMessage(location);
        }

        @Override
        public void onStatusChanged(String s, int i, Bundle bundle) {}

        @Override
        public void onProviderEnabled(String s) {}

        @Override
        public void onProviderDisabled(String s) {}
    };

    @Override
    @TargetApi(Build.VERSION_CODES.M)
    public void onCreate() {
        locationManager = getSystemService(LocationManager.class);

        int permissionCheck = ContextCompat.checkSelfPermission(this,
                android.Manifest.permission.ACCESS_FINE_LOCATION);
        if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 500, 1, locationListener);
        }
    }

    private void sendMessage(Location location) {
        try {
            Intent intent = new Intent("GeoLocationUpdate");
            intent.putExtra("message", location);
            LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onDestroy() {
        locationManager.removeUpdates(locationListener);
        super.onDestroy();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        startForeground(GEOLOCATION_NOTIFICATION_ID, getCompatNotification());
        return START_STICKY;
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    private Notification getCompatNotification() {
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        String str = "Is using your location in the background";
        builder
                .setSmallIcon(com.prop.R.mipmap.ic_gps_icon)
                .setLargeIcon(BitmapFactory.decodeResource(getResources(), com.prop.R.mipmap.ic_gps_icon))
                .setContentTitle("App Name")
                .setContentText(str)
                .setTicker(str)
                .setWhen(System.currentTimeMillis());
        Intent startIntent = new Intent(getApplicationContext(), MainActivity.class);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 1000, startIntent, 0);
        builder.setContentIntent(contentIntent);
        return builder.build();
    }
}

请帮我解释为什么android方面没有发射或js方面没有接收事件。我的Android清单中有以下权限：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>