android观察者模式：EventBus实现GPS定位

package com.scut.eventbusdemo.service; import android.app.Service; import android.content.Context; import android.content.Intent; import android.location.Criteria; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.os.IBinder; import android.util.Log; import com.scut.eventbusdemo.model.LocationMessage; import de.greenrobot.event.EventBus; /** * GPS定位服务 * victor shi * 2015/12/9 */ public class LocationService extends Service implements LocationListener{ // flag for GPS status boolean isGPSEnabled = false; // flag for network status boolean isNetworkEnabled = false; // flag for GPS status boolean canGetLocation = false; Location location; // location String provider; // The minimum distance to change Updates in meters private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 0 meters // The minimum time between updates in milliseconds private static final long MIN_TIME_BW_UPDATES = 1000 * 10 * 1; // 10 seconds //LocationManager对象 private LocationManager locationManager; @Override public void onCreate() { super.onCreate(); Log.i("service", "onCreate"); //获取系统locationManager服务 locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); Criteria criteria = new Criteria(); // 获得最好的定位效果 criteria.setAccuracy(Criteria.ACCURACY_FINE); criteria.setAltitudeRequired(false); criteria.setBearingRequired(false); criteria.setCostAllowed(false); // 使用省电模式 criteria.setPowerRequirement(Criteria.POWER_LOW); // 获得当前的位置提供者 provider = locationManager.getBestProvider(criteria, true); } @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.i("service", "onStartCommand"); getLocation(); return super.onStartCommand(intent, flags, startId); } /* 通过网络或GPS获取定位信息 */ public Location getLocation() { try { // getting GPS status isGPSEnabled = locationManager .isProviderEnabled(LocationManager.GPS_PROVIDER); // getting network status isNetworkEnabled = locationManager .isProviderEnabled(LocationManager.NETWORK_PROVIDER); if (!isGPSEnabled && !isNetworkEnabled) { // no network provider is enabled } else { this.canGetLocation = true; // First get location from Network Provider if (isNetworkEnabled) { locationManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); if (locationManager != null) { location = locationManager .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); } } // if GPS Enabled get lat/long using GPS Services if (isGPSEnabled) { if (location == null) { locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); if (locationManager != null) { location = locationManager .getLastKnownLocation(provider); } } } } } catch (Exception e) { e.printStackTrace(); } return location; } private void updateMessage(Location location) { if(location != null) { Log.i("service", "msg != null"); EventBus.getDefault().post(new LocationMessage(location)); } else { Log.i("service", "msg = null"); EventBus.getDefault().post(new LocationMessage()); } } @Override public IBinder onBind(Intent intent) { return null; } @Override public void onLocationChanged(Location location) { Log.i("locationListener", "onLocationChanged"); updateMessage(location); } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } @Override public void onProviderEnabled(String provider) { } @Override public void onProviderDisabled(String provider) { } }