问题
I am able to implement a simple gpsTracker using a service that runs on background like this:
public class MyService extends Service
{
private static final String TAG = "BOOMBOOMTESTGPS";
private LocationManager mLocationManager = null;
private static final int LOCATION_INTERVAL = 1000;
private static final float LOCATION_DISTANCE = 10f;
private final IBinder mBinder = new LocalBinder();
private Intent intent;
Context context;
Location mLastLocation;
public class LocalBinder extends Binder {
public MyService getServerInstance() {
return MyService.this;
}
}
public Location getLocation(){
return mLastLocation;
}
private class LocationListener implements android.location.LocationListener
{
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);
Log.d("HELLO",String.valueOf(mLastLocation.getLatitude()));
}
@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);
}
}
LocationListener[] mLocationListeners = new LocationListener[] {
new LocationListener(LocationManager.GPS_PROVIDER),
new LocationListener(LocationManager.NETWORK_PROVIDER)
};
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Log.e(TAG, "onStartCommand");
context = getApplicationContext();
super.onStartCommand(intent, flags, startId);
return START_STICKY;
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public void onCreate()
{
Log.e(TAG, "onCreate");
initializeLocationManager();
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");
super.onDestroy();
if (mLocationManager != null) {
for (int i = 0; i < mLocationListeners.length; i++) {
try {
mLocationManager.removeUpdates(mLocationListeners[i]);
} catch (Exception ex) {
Log.i(TAG, "fail to remove location listners, ignore", ex);
}
}
}
}
private void initializeLocationManager() {
Log.e(TAG, "initializeLocationManager");
mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (mLocationManager == null) {
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
}
and after this i i start the service on a main activity like this:
public class MainActivity extends AppCompatActivity {
private BroadcastReceiver receiver;
IntentFilter filter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void initService(View view){
checkPermissions();
startService(new Intent(this, MyService.class)); // inicia um serviço de obtenção de coordenadas GPS
}
private void checkPermissions() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION},
30);
}
}
}
public void nextAct(View view){
Intent i = new Intent(this,GpsGetCoordinates.class);
startActivity(i);
}
}
i already get the location when i desire, but how can i get the location when i restart the application? it just works when i provide a location if the user starts the app and doesn't move it faill any tip on this?
回答1:
Well You have to start the service in two cases:-
1) When user grant the location access.
2)When user already granted the permission after launching application again.
So you have to handle both the ways
Try this.
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
public boolean checkLocationPermission() {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission. ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission. ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
new AlertDialog.Builder(this)
.setTitle(R.string.title_location_permission)
.setMessage(R.string.text_location_permission)
.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
})
.create()
.show();
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission. ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// location-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
Manifest.permission. ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
//start your service here
startService(new Intent(this, MyService.class));
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
}
}
The in OnResume() do this
@Override
protected void onResume() {
super.onResume();
if (checkLocationPermission()) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission. ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
//start your service here
startService(new Intent(this, MyService.class));
}
}
}
No need to Call this Method in onCreate()
public void initService(View view){
// no need to initialize permission and service class here
}
来源：https://stackoverflow.com/questions/44476109/how-to-start-service-again-when-app-restarts-and-user-already-granted-location-a