有时定位服务无法在后台运行

Question

我在我的android 应用程序中使用了Location Service，它扩展了Service 并实现了GoogleApiClient、LocationListener。我正在更新位置 onLocationChanged() 方法，我的位置更新间隔为 20 秒。有时即使应用程序在后台，定位服务也无法正常工作。无论如何，我想始终运行我的位置服务。每个版本的 Android 和每个手机，即使该应用程序也在后台杀戮。 我也使用 AlarmManager 调用位置服务。 我在 onStartCommand() 方法中调用了位置更新。 如果位置服务停止，那么它将再次转到该方法中的 onDestroy() 方法或 onTaskRemoved() 方法我正在调用 startLocation 方法，例如，

startService(new Intent(this, LocationService.class));

我的服务清单代码：

<service
        android:name=".LocationService"
        android:enabled="true"
        android:stopWithTask="false"
        />

Answer 1

您可以创建如下位置服务。在后台和前台模式下运行

public class ServiceLocation extends Service implements
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

    private static final String NOTIFICATION_CHANNEL_ID = "my_notification_location";
    private static final long TIME_INTERVAL_GET_LOCATION = 1000 * 5; // 1 Minute
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 7; // meters

    private Handler handlerSendLocation;
    private Context mContext;

    private GoogleApiClient mGoogleApiClient;
    private LocationRequest mLocationRequest;

    private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 5000;

    Location locationData;

    @Override
    public void onCreate() {
        super.onCreate();

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();

        // Create the LocationRequest object
        mLocationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(TIME_INTERVAL_GET_LOCATION)    // 3 seconds, in milliseconds
                .setFastestInterval(TIME_INTERVAL_GET_LOCATION); // 1 second, in milliseconds

        mContext = this;


        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID)
                .setOngoing(false)
                .setSmallIcon(R.drawable.ic_notification)
                .setColor(getResources().getColor(R.color.fontColorDarkGray))
                .setPriority(Notification.PRIORITY_MIN);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,
                    NOTIFICATION_CHANNEL_ID, NotificationManager.IMPORTANCE_LOW);
            notificationChannel.setDescription(NOTIFICATION_CHANNEL_ID);
            notificationChannel.setSound(null, null);
            notificationManager.createNotificationChannel(notificationChannel);
            startForeground(1, builder.build());
        }
    }

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        Log.w("Service Update Location", "BGS > Started");

        if (handlerSendLocation == null) {
            handlerSendLocation = new Handler();
            handlerSendLocation.post(runnableSendLocation);
            Log.w("Service Send Location", "BGS > handlerSendLocation Initialized");
        } else {
            Log.w("Service Send Location", "BGS > handlerSendLocation Already Initialized");
        }

        return START_STICKY;
    }

    private Runnable runnableSendLocation = new Runnable() {

        @Override
        public void run() {


            // You can get Location
            //locationData and Send Location X Minutes
            if (locationData != null) {
                Intent intent = new Intent("GPSLocationUpdates");
                intent.putExtra("Latitude", "" + locationData.getLatitude());
                intent.putExtra("Longitude", "" + locationData.getLongitude());


                LocalBroadcastManager.getInstance(mContext).sendBroadcast(intent);

                Log.w("==>UpdateLocation<==", "" + String.format("%.6f", locationData.getLatitude()) + "," +
                        String.format("%.6f", locationData.getLongitude()));

                Log.w("Service Send Location", "BGS >> Location Updated");
            }
            if (handlerSendLocation != null && runnableSendLocation != null)
                handlerSendLocation.postDelayed(runnableSendLocation, TIME_INTERVAL_GET_LOCATION);
        }
    };


    @Override
    public void onConnected(@Nullable Bundle bundle) {
        if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            return;
        }


        FusedLocationProviderClient mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
        mFusedLocationClient.requestLocationUpdates(mLocationRequest, new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                locationData = locationResult.getLastLocation();
            }
        }, null);
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        if (connectionResult.hasResolution() && mContext instanceof Activity) {
            try {
                Activity activity = (Activity) mContext;
                connectionResult.startResolutionForResult(activity, CONNECTION_FAILURE_RESOLUTION_REQUEST);
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
            Log.i("", "Location services connection failed with code " + connectionResult.getErrorCode());
        }
    }

    @Override
    public void onLocationChanged(Location location) {
        Log.w("==>UpdateLocation<==", "" + String.format("%.6f", location.getLatitude()) + "," + String.format("%.6f", location.getLongitude()));
        locationData = location;

    }

    @Override
    public void onDestroy() {

        if (handlerSendLocation != null)
            handlerSendLocation.removeCallbacks(runnableSendLocation);


        Log.w("Service Update Info", "BGS > Stopped");

        stopSelf();
        super.onDestroy();
    }


}

在 android manifest 文件中声明此服务，如下所示

<service
            android:name=".ServiceLocation"
            android:enabled="true"
            android:exported="true" />

您可以使用此代码从活动中启动服务

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
     ContextCompat.startForegroundService(MainActivity.this, new Intent(MainActivity.this, ServiceLocation.class));
 } else {
     startService(new Intent(MainActivity.this, ServiceLocation.class));
 }