Android 定位服务无法在后台运行

Question

我正在开发一个 Location-App，当用户按下 Button 时，它应该开始根据经度和纬度跟踪一些统计数据。所有这些东西都很好用，但是当涉及到锁定屏幕或将应用程序置于后台时，该服务不再工作了!

我已经阅读了很多关于后台服务和广播接收器的内容，但我不知道如何在服务中实现 Google API 位置监听器以及在 MainActivity 中的何处实现此类。任何人都可以用一个简短的代码示例告诉我如何实现这样的服务或解释这个的链接吗？

Answer 1

使用 fuse 定位服务并每次保存更新的位置

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

    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    public static Location mCurrentLocation;

    .............................

    @Override
    public void onCreate() {

        //show error dialog if GoolglePlayServices not available
        if (isGooglePlayServicesAvailable()) {
            mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(BACKGROUND_INTERVAL);  
        mLocationRequest.setFastestInterval(BACKGROUND_INTERVAL);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        //mLocationRequest.setSmallestDisplacement(10.0f);  /* min dist for location change, here it is 10 meter */
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addApi(LocationServices.API)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .build();

            mGoogleApiClient.connect();
        }
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
         return super.onStartCommand(intent, flags, startId);
    }

    //Check Google play is available or not
    private boolean isGooglePlayServicesAvailable() {
        int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());
        return ConnectionResult.SUCCESS == status;
    }


    @Override
    public void onConnected(Bundle bundle) {
        startLocationUpdates();
    }

    protected void startLocationUpdates() {
        try {
             PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.requestLocationUpdates(
                    mGoogleApiClient, mLocationRequest, this);
        } catch (IllegalStateException e) {}
    }

    @Override
    public void onLocationChanged(Location location) {

        //Save your location
    }
    ............................
}

你可以获取当前位置 onLocationChanged()

更多详情请查看http://javapapers.com/android/android-location-fused-provider/或按照官方指南https://developer.android.com/training/location/index.html