我为了得到我的应用程序的当前用户的最后位置开始从活动（TrackerActivity）服务（TrackerService）。那么我告诉登录一个火力地堡DB当前用户的实时位置和我的应用程序（在LentiMapsActivity）的所有用户的标记。
最后，我尝试停止服务为LentiMapsActivity并返回到与MainActivity：
@Override
protected void onStop() {
Intent intent = new Intent(LentiMapsActivity.this,TrackerService.class);
stopService (intent);
Log.d(TAG,"Stop the service");
super.onStop();
}
但服务仍然运行。
在这里我为TrackerService代码
public class TrackerService extends Service {
private FirebaseAuth mAuth;
private static final String TAG = TrackerService.class.getSimpleName();
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_NOT_STICKY;
}
@Override
public void onCreate() {
super.onCreate();
requestLocationUpdates();
}
@Override
public void onDestroy() {
stopSelf(2);
Log.d(TAG,"Start onDestroy");
}
private void requestLocationUpdates() {
LocationRequest request = new LocationRequest();
request.create();
request.setInterval(10000);
request.setFastestInterval(5000);
request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);
int permission = ContextCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION);
if (permission == PackageManager.PERMISSION_GRANTED) {
client.requestLocationUpdates(request, new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
final String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference latlongRef = rootRef.child("Users").child(uid).child("latlong");
Location location = locationResult.getLastLocation();
if (location != null) {
Log.d(TAG, "location update " + location);
latlongRef.setValue(location);
}
}
}, null);
}
}
}
和LentiMapsActivity
public class LentiMapsActivity extends FragmentActivity implements OnMapReadyCallback{
private GoogleMap mMap;
private static final String TAG = LentiMapsActivity.class.getSimpleName();
List<String> localList;
private static final int PERMISSIONS_REQUEST = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lenti_maps);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
localList = new ArrayList<String>();
Intent intent = new Intent(LentiMapsActivity.this, TrackerActivity.class);
startActivity(intent);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setMaxZoomPreference(16);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
== PackageManager.PERMISSION_GRANTED
|| ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
mMap.setMyLocationEnabled(true);
}
loadUsers ();
}
private void loadUsers() {
final String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
final DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
final DatabaseReference usersRef = rootRef.child("Users");
rootRef.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
String key = dataSnapshot1.getKey();
localList.add(key);
Local localCurrent = dataSnapshot.child(uid).child("latlong").getValue(Local.class);
LatLng latLngCurrent = new LatLng(localCurrent.getLatitude(),localCurrent.getLongitude());
for (int i = 0; i<localList.size(); i++)
{
Local local = dataSnapshot.child(key).child("latlong").getValue(Local.class);
Local nick = dataSnapshot.child(key).getValue(Local.class);
if (local != null){
LatLng latLng = new LatLng(local.getLatitude(),local.getLongitude());
if (mMap != null)
{
mMap.addMarker(new MarkerOptions().position(latLng).title(nick.getNickname()));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLngCurrent,11));
}
}
}
}
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
@Override
protected void onStop() {
Intent intent = new Intent(LentiMapsActivity.this,TrackerService.class);
stopService (intent);
Log.d(TAG,"Stop the service");
super.onStop();
}
}
从日志：
D/FA: Connected to remote service
V/FA: Processing queued up service tasks: 4
D/EGL_emulation: eglMakeCurrent: 0x99315f40: ver 2 0 (tinfo 0x99338c00)
D/LentiMapsActivity: Stop the service
D/TrackerService: Start onDestroy
D/TrackerService: location update Location[fused 45.460000,9.150000 acc=12 et=+5d21h19m25s455ms vel=0.0 bear=0.0]
V/FA: Inactivity, disconnecting from the service
D/TrackerService: location update Location[fused 45.460000,9.150000 acc=12 et=+5d21h19m30s458ms vel=0.0 bear=0.0]
D/TrackerService: location update Location[fused 45.460000,9.150000 acc=12 et=+5d21h19m35s460ms vel=0.0 bear=0.0]
D/TrackerService: location update Location[fused 45.460000,9.150000 acc=12 et=+5d21h19m41s463ms vel=0.0 bear=0.0]
你Service，着实被摧毁。但是，这并不一定意味着你的应用程序被终止;根据Android的版本使用的是，它可以继续从几秒钟的任何地方存在，许多天。
在您的应用程序没有结束的情况下，你的代码没有提供方法来禁用位置更新。该解决方案，在这种情况下，是添加调用removeLocationUpdates()您TrackerService.onDestroy()方法。
编辑
示例代码：
public class TrackerService extends Service {
...
private LocationCallback mLocationCallback = new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
final String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference latlongRef = rootRef.child("Users").child(uid).child("latlong");
Location location = locationResult.getLastLocation();
if (location != null) {
Log.d(TAG, "location update " + location);
latlongRef.setValue(location);
}
}
};
...
@Override
public void onDestroy() {
//No need to call this; the Service is already stopping:
//stopSelf(2);
FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);
client.removeLocationUpdates(mLocationCallback);
Log.d(TAG,"Start onDestroy");
}
private void requestLocationUpdates() {
LocationRequest request = new LocationRequest();
request.create();
request.setInterval(10000);
request.setFastestInterval(5000);
request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);
int permission = ContextCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION);
if (permission == PackageManager.PERMISSION_GRANTED) {
client.requestLocationUpdates(request, mLocationCallback, null);
}
}
}