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问题:
Actually my problem is I am not getting current location latitude and longitude I tried so many ways.I know that this question already asked in SO I tried that answers also still I didn't get answer.Please help me Code:
if (googleMap == null) { googleMap = ((MapFragment) getFragmentManager().findFragmentById( R.id.map)).getMap(); // check if map is created successfully or not if (googleMap == null) { Toast.makeText(getApplicationContext(), "Sorry! unable to create maps", Toast.LENGTH_SHORT) .show(); } } googleMap.setMyLocationEnabled(true); Location myLocation = googleMap.getMyLocation(); //Nullpointer exception......... LatLng myLatLng = new LatLng(myLocation.getLatitude(), myLocation.getLongitude()); CameraPosition myPosition = new CameraPosition.Builder() .target(myLatLng).zoom(17).bearing(90).tilt(30).build(); googleMap.animateCamera( CameraUpdateFactory.newCameraPosition(myPosition));
回答1:
Please check the sample code for the Google Maps Android API v2. Using this will solve your problem.
private void setUpMapIfNeeded() { // Do a null check to confirm that we have not already instantiated the map. if (mMap == null) { // Try to obtain the map from the SupportMapFragment. mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)) .getMap(); mMap.setMyLocationEnabled(true); // Check if we were successful in obtaining the map. if (mMap != null) { mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() { @Override public void onMyLocationChange(Location arg0) { // TODO Auto-generated method stub mMap.addMarker(new MarkerOptions().position(new LatLng(arg0.getLatitude(), arg0.getLongitude())).title("It's Me!")); } }); } } }
Call this function in onCreate function.
回答2:
I think that better way now is:
Location currentLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
Documentation. Getting the Last Known Location
回答3:
package com.example.sandeep.googlemapsample; import android.content.pm.PackageManager; import android.location.Location; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.v4.app.ActivityCompat; import android.support.v4.app.FragmentActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Toast; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.api.GoogleApiClient; import com.google.android.gms.location.LocationServices; import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.OnMapReadyCallback; import com.google.android.gms.maps.SupportMapFragment; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.Marker; import com.google.android.gms.maps.model.MarkerOptions; public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, GoogleMap.OnMarkerDragListener, GoogleMap.OnMapLongClickListener, GoogleMap.OnMarkerClickListener, View.OnClickListener { private static final String TAG = "MapsActivity"; private GoogleMap mMap; private double longitude; private double latitude; private GoogleApiClient googleApiClient; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_maps); // Obtain the SupportMapFragment and get notified when the map is ready to be used. SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.map); mapFragment.getMapAsync(this); //Initializing googleApiClient googleApiClient = new GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .addOnConnectionFailedListener(this) .addApi(LocationServices.API) .build(); } @Override public void onMapReady(GoogleMap googleMap) { mMap = googleMap; mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID); // googleMapOptions.mapType(googleMap.MAP_TYPE_HYBRID) // .compassEnabled(true); // Add a marker in Sydney and move the camera LatLng india = new LatLng(-34, 151); mMap.addMarker(new MarkerOptions().position(india).title("Marker in India")); mMap.moveCamera(CameraUpdateFactory.newLatLng(india)); mMap.setOnMarkerDragListener(this); mMap.setOnMapLongClickListener(this); } //Getting current location private void getCurrentLocation() { mMap.clear(); 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; } Location location = LocationServices.FusedLocationApi.getLastLocation(googleApiClient); if (location != null) { //Getting longitude and latitude longitude = location.getLongitude(); latitude = location.getLatitude(); //moving the map to location moveMap(); } } private void moveMap() { /** * Creating the latlng object to store lat, long coordinates * adding marker to map * move the camera with animation */ LatLng latLng = new LatLng(latitude, longitude); mMap.addMarker(new MarkerOptions() .position(latLng) .draggable(true) .title("Marker in India")); mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng)); mMap.animateCamera(CameraUpdateFactory.zoomTo(15)); mMap.getUiSettings().setZoomControlsEnabled(true); } @Override public void onClick(View view) { Log.v(TAG,"view click event"); } @Override public void onConnected(@Nullable Bundle bundle) { getCurrentLocation(); } @Override public void onConnectionSuspended(int i) { } @Override public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { } @Override public void onMapLongClick(LatLng latLng) { // mMap.clear(); mMap.addMarker(new MarkerOptions().position(latLng).draggable(true)); } @Override public void onMarkerDragStart(Marker marker) { Toast.makeText(MapsActivity.this, "onMarkerDragStart", Toast.LENGTH_SHORT).show(); } @Override public void onMarkerDrag(Marker marker) { Toast.makeText(MapsActivity.this, "onMarkerDrag", Toast.LENGTH_SHORT).show(); } @Override public void onMarkerDragEnd(Marker marker) { // getting the Co-ordinates latitude = marker.getPosition().latitude; longitude = marker.getPosition().longitude; //move to current position moveMap(); } @Override protected void onStart() { googleApiClient.connect(); super.onStart(); } @Override protected void onStop() { googleApiClient.disconnect(); super.onStop(); } @Override public boolean onMarkerClick(Marker marker) { Toast.makeText(MapsActivity.this, "onMarkerClick", Toast.LENGTH_SHORT).show(); return true; } }
回答4:
Your current location might not be available immediately, after the map fragment is initialized.
After set
googleMap.setMyLocationEnabled(true);
you have to wait until you see the blue dot shown on your MapView. Then
Location myLocation = googleMap.getMyLocation();
myLocation won't be null.
I think you better use the LocationClient instead, and implement your own LocationListener.onLocationChanged(Location l)
Receiving Location Updates will show you how to get current location from LocationClient
回答5:
Add the permissions to the app manifest
Add one of the following permissions as a child of the element in your Android manifest. Either the coarse location permission:
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.myapp" > ... <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> ... </manifest>
Or the fine location permission:
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.myapp" > ... <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> ... </manifest>
The following code sample checks for permission using the Support library before enabling the My Location layer:
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) { mMap.setMyLocationEnabled(true); } else { // Show rationale and request permission. } The following sample handles the result of the permission request by implementing the ActivityCompat.OnRequestPermissionsResultCallback from the Support library: @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { if (requestCode == MY_LOCATION_REQUEST_CODE) { if (permissions.length == 1 && permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION && grantResults[0] == PackageManager.PERMISSION_GRANTED) { mMap.setMyLocationEnabled(true); } else { // Permission was denied. Display an error message. } }
This example provides current location update using GPS provider. Entire Android app code is as follows,
import android.os.Bundle; import android.app.Activity; import android.content.Context; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.widget.TextView; import android.util.Log; public class MainActivity extends Activity implements LocationListener{ protected LocationManager locationManager; protected LocationListener locationListener; protected Context context; TextView txtLat; String lat; String provider; protected String latitude,longitude; protected boolean gps_enabled,network_enabled; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txtLat = (TextView) findViewById(R.id.textview1); locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this); } @Override public void onLocationChanged(Location location) { txtLat = (TextView) findViewById(R.id.textview1); txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude()); } @Override public void onProviderDisabled(String provider) { Log.d("Latitude","disable"); } @Override public void onProviderEnabled(String provider) { Log.d("Latitude","enable"); } @Override public void onStatusChanged(String provider, int status, Bundle extras) { Log.d("Latitude","status"); } }
回答6:
public void getMyLocation() { // create class object gps = new GPSTracker(HomeActivity.this); // check if GPS enabled if (gps.canGetLocation()) { latitude = gps.getLatitude(); longitude = gps.getLongitude(); Geocoder geocoder; List<Address> addresses; geocoder = new Geocoder(this, Locale.getDefault()); try { addresses = geocoder.getFromLocation(latitude, longitude, 1); postalCode = addresses.get(0).getPostalCode(); city = addresses.get(0).getLocality(); address = addresses.get(0).getAddressLine(0); state = addresses.get(0).getAdminArea(); country = addresses.get(0).getCountryName(); knownName = addresses.get(0).getFeatureName(); Log.e("Location",postalCode+" "+city+" "+address+" "+state+" "+knownName); } catch (IOException e) { e.printStackTrace(); } } else { gps.showSettingsAlert(); } }
回答7:
Why not to use FusedLocationApi instead of OnMyLocationChangeListener? You need to initialize GoogleApiClient object and use LocationServices.FusedLocationApi.requestLocationUpdates() method to register location change listener. It is important to note, that don't forget to remove the registered listener and disconnect GoogleApiClient.
private LocationRequest mLocationRequest; private GoogleApiClient mGoogleApiClient; private LocationListener mLocationListener; private void initGoogleApiClient(Context context) { mGoogleApiClient = new GoogleApiClient.Builder(context).addApi(LocationServices.API).addConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() { @Override public void onConnected(Bundle bundle) { mLocationRequest = LocationRequest.create(); mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); mLocationRequest.setInterval(1000); setLocationListener(); } @Override public void onConnectionSuspended(int i) { Log.i("LOG_TAG", "onConnectionSuspended"); } }).build(); if (mGoogleApiClient != null) mGoogleApiClient.connect(); } private void setLocationListener() { mLocationListener = new LocationListener() { @Override public void onLocationChanged(Location location) { String lat = String.valueOf(location.getLatitude()); String lon = String.valueOf(location.getLongitude()); Log.i("LOG_TAG", "Latitude = " + lat + " Longitude = " + lon); } }; LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, mLocationListener); } private void removeLocationListener() { LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, mLocationListener); }
回答8:
public class MainActivity extends ActionBarActivity implements ConnectionCallbacks, OnConnectionFailedListener { ... @Override public void onConnected(Bundle connectionHint) { mLastLocation = LocationServices.FusedLocationApi.getLastLocation( mGoogleApiClient); if (mLastLocation != null) { mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude())); mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude())); } } }
