【发布时间】:2017-05-02 06:10:53
【问题描述】:
我正在使用位置侦听器服务每隔几秒更新一次用户的当前位置。我还使用了 WakeLock 让监听器在后台工作。现在一切正常,但我无法停止 Location 监听器。即使应用程序被强制关闭,侦听器也会将用户位置更新到数据库。
位置监听器:
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.os.PowerManager;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import android.widget.Toast;
import com.google.android.gms.maps.model.LatLng;
public class MyLocationService extends Service {
private static final String TAG = "MyLocationService";
private LocationManager mLocationManager = null;
private static final int LOCATION_INTERVAL = 3000;
private static final float LOCATION_DISTANCE = 0f;
Context context = this;
PowerManager.WakeLock wakeLock;
public int e=0;
LocationListener[] mLocationListeners = new LocationListener[]{
new LocationListener(LocationManager.GPS_PROVIDER),
new LocationListener(LocationManager.NETWORK_PROVIDER)
};
@Override
public IBinder onBind(Intent arg0) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.e(TAG, "onStartCommand");
super.onStartCommand(intent, flags, startId);
Toast.makeText(this, "MyService Started.", Toast.LENGTH_SHORT).show();
return START_STICKY;
}
@Override
public void onCreate() {
Log.e(TAG, "onCreate");
initializeLocationManager();
PowerManager mgr = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
wakeLock= mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");
wakeLock.acquire();
try {
mLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[1]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "network provider does not exist, " + ex.getMessage());
}
try {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[0]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "gps provider does not exist " + ex.getMessage());
}
}
@Override
public void onDestroy() {
Log.e(TAG, "onDestroy");
wakeLock.release();
super.onDestroy();
if (mLocationManager != null) {
for (int i = 0; i < mLocationListeners.length; i++) {
try {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
mLocationManager.removeUpdates(mLocationListeners[i]);
} catch (Exception ex) {
Log.i(TAG, "fail to remove location listners, ignore", ex);
}
}
}
}
private void initializeLocationManager() {
Log.e(TAG, "initializeLocationManager");
if (mLocationManager == null) {
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
}
// create LocationListener class to get location updates
private class LocationListener implements android.location.LocationListener
{
Location mLastLocation;
double latitude;
double longitude;
LatLng latLngcurrent;
public LocationListener(String provider)
{
Log.e(TAG, "LocationListener " + provider);
mLastLocation = new Location(provider);
}
@Override
public void onLocationChanged(Location location)
{
Log.e(TAG, "onLocationChanged: " + location);
mLastLocation.set(location);
latitude = location.getLatitude();
longitude = location.getLongitude();
Store.latu=latitude;
Store.longu=longitude;
latLngcurrent = new LatLng(location.getLatitude(), location.getLongitude());
Toast.makeText(context,"Location " + String.valueOf(e), Toast.LENGTH_SHORT).show();
e++;
Toast.makeText(MyLocationService.this,Store.latu+" "+Store.longu, Toast.LENGTH_SHORT).show();
}
@Override
public void onProviderDisabled(String provider)
{
Log.e(TAG, "onProviderDisabled: " + provider);
}
@Override
public void onProviderEnabled(String provider)
{
Log.e(TAG, "onProviderEnabled: " + provider);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
Log.e(TAG, "onStatusChanged: " + provider);
}
}
}
启动服务意图:(来自 mainactivity)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
Intent serviceIntent = new Intent(context , MyLocationService.class);
context.startService(serviceIntent );
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkLocationPermission();
}
if (!isGooglePlayServicesAvailable()) {
finish();
} else {
Log.d("onCreate", "Google Play Services available.");
}
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
停止意图:(来自 mainactivity)
private class LogOutTimerTask extends TimerTask
{
@Override
public void run()
{
Intent i = new Intent(MapsActivity.this, Login.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
Intent intent = new Intent(MapsActivity.this, MyLocationService.class);
stopService(intent);
finish();
}
}
停止意图在用户注销时被调用,现在服务类中的 onDestroy() 方法被调用但它并没有停止进程。当应用程序被强制关闭时,甚至不会调用 onDestroy()。在这两种情况下,流程都会恢复并继续将值更新到 DB。提前致谢。
【问题讨论】:
-
removeUpdates()被调用了吗?或者由于权限IF而返回该方法?但是,为什么在删除侦听器时要检查权限?这应该在initializeLocationManager()内或附近的某个地方 -
我没有检查 removeupdates() 是否被调用。我添加了权限,因为 android studio 向我推荐。 @亚赞
-
我怀疑这个地方是否适合请求许可(同时破坏服务?!)但是,将它放在循环中并不是很好,你可以请求一次(在循环之前) 还尝试在
removeUpdates()之前添加一个日志,类似于Log.i(TAG, "removing listeners ...");并查看它是否出现在 logcat 中 -
我已经删除了权限检查并添加了 log(),现在当我注销时,日志值正在打印,然后服务停止。但是当应用程序从后台强制关闭时,服务不会被终止,并且 onDestroy 也不会被调用。 @亚赞
-
好的,这是另一个问题,我建议您单独问,但我认为它与
return START_STICKY;有关此主题需要阅读,以便您了解服务在应用程序终止、重新启动时的行为。 ..等
标签: android intentservice wakelock locationlistener android-wake-lock