java – 播放位置服务getLastLocation返回null

注意

如果我重新启动设备,位置服务将仅工作约2天;之后,当谷歌地图仍然有效时,我的应用程序和the SDK example都不会正常工作.

这是我的服务代码：

public class VisitService extends Service implements
        GooglePlayServicesClient.ConnectionCallbacks,GooglePlayServicesClient.OnConnectionFailedListener,LocationListener {

    private final IBinder mBinder = new VisitBinder();


    // A request to connect to Location Services
    private LocationRequest mLocationRequest;

    // Stores the current instantiation of the location client in this object
    private LocationClient mLocationClient;


    private boolean mLocationServiceConnected = false;

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

    @Override
    public IBinder onBind(Intent intent) {
        initLocation();
        return mBinder;
    }

    public void startVisit() {
        if (!servicesConnected()) {
            listener.onVisitStartError();
            return;
        }

        if (mLocationServiceConnected) {
            if (isAcceptableLocation(mLocationClient.getLastLocation())) {
                Toast.makeText(this,"You have arrived!",Toast.LENGTH_LONG);
            } else {
                mVisitListener.onVisitStartError();
            }
        }    
    }

    private boolean isAcceptableLocation(Location location) {
        if (location == null) {
            Toast.makeText(this,"Location is null",Toast.LENGTH_LONG).show();
            return false;
        }

        return true;
    }


    private void initLocation() {

        if (mLocationRequest == null) {
            // Create a new global location parameters object
            mLocationRequest = LocationRequest.create();
            /*
             * Set the update interval
             */
            mLocationRequest
                    .setInterval(LocationUtils.UPDATE_INTERVAL_IN_MILLISECONDS);

            // Use high accuracy
            mLocationRequest
                    .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

            // Set the interval ceiling to one minute
            mLocationRequest
                    .setFastestInterval(LocationUtils.FAST_INTERVAL_CEILING_IN_MILLISECONDS);

        }

        if (mLocationClient == null) {
            mLocationClient = new LocationClient(this,this,this);
            mLocationClient.connect();
        }
    }

    /**
     * Verify that Google Play services is available before making a request.
     * 
     * @return true if Google Play services is available,otherwise false
     */
    private boolean servicesConnected() {

        // Check that Google Play services is available
        int resultCode = GooglePlayServicesUtil
                .isGooglePlayServicesAvailable(this);

        // If Google Play services is available
        if (ConnectionResult.SUCCESS == resultCode) {
            // In debug mode,log the status
            Log.d(LocationUtils.APPTAG,getString(R.string.play_services_available));

            return true;
        } else {

            return false;
        }
    }

    public class VisitBinder extends Binder {
        public VisitService getService() {
            return VisitService.this;
        }
    }


    /**
     * In response to a request to start updates,send a request to Location
     * Services
     */
    private void startPeriodicUpdates() {

        mLocationClient.requestLocationUpdates(mLocationRequest,this);
        Toast.makeText(this,"Location Update Requested",Toast.LENGTH_LONG).show();
    }

    /**
     * In response to a request to stop updates,send a request to Location
     * Services
     */
    private void stopPeriodicUpdates() {
        mLocationClient.removeLocationUpdates(this);

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.d(LocationUtils.APPTAG,"Location Services Connection faild");


    }

    @Override
    public void onConnected(Bundle bundle) {
        Log.d(LocationUtils.APPTAG,"Location Services Connected");
        mLocationServiceConnected = true;
        startPeriodicUpdates();
    }

    @Override
    public void onDisconnected() {
        mLocationServiceConnected = false;
    }

    @Override
    public void onLocationChanged(Location location) {
        Toast.makeText(this,"Location has been changed",Toast.LENGTH_LONG).show();
    }
}

Android Manifest

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