Question

我已拨打setMyLocationEnabled(true)，但未显示我当前的位置。请指教。

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback
{
    private GoogleMap mMap;
    /**
     * ATTENTION: This was auto-generated to implement the App Indexing API.
     * See https://g.co/AppIndexing/AndroidStudio for more information.
     */
    private GoogleApiClient client;

    @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);
        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // Add a marker in Sydney and move the camera
        LatLng sydney = new LatLng(-34, 151);
        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));

        if (mMap.isMyLocationEnabled()) {
            mMap.setMyLocationEnabled(true);
        } else {
            showSettingsAlert();
        }
    }

    private void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
        alertDialog.setTitle("GPS is settings");
        alertDialog.setMessage("GPS is not enalbled. Do you want to go to settings menu?");
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(intent);
            }
        });

        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        alertDialog.show();
    }
}

清单

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>

错误

 FATAL EXCEPTION: main
                                                           Process: com.companero, PID: 25005
                                                           java.lang.IllegalStateException: MyLocation layer not enabled
                                                               at maps.f.g.b(Unknown Source)
                                                               at maps.ag.t.j(Unknown Source)
                                                               at uz.onTransact(:com.google.android.gms.DynamiteModulesB:281)
                                                               at android.os.Binder.transact(Binder.java:387)
                                                               at com.google.android.gms.maps.internal.IGoogleMapDelegate$zza$zza.getMyLocation(Unknown Source)
                                                               at com.google.android.gms.maps.GoogleMap.getMyLocation(Unknown Source)

非常感谢！

Answer 1

您的GoogleMap有时需要一段时间才能加载，因此Location可能是null。

if (mMap != null) {
    mMap.setMyLocationEnabled(true);
}

放手一搏：

if (mMap != null) {
    Location myLocation = mMap.getMyLocation();

    if (myLocation != null) {
        LatLng myLatLng = new LatLng(myLocation.getLatitude(), myLocation.getLongitude());

        CameraPosition myPosition = new CameraPosition.Builder().target(myLatLng).zoom(17).bearing(90).tilt(30).build();
        map.animateCamera(CameraUpdateFactory.newCameraPosition(myPosition));
   }
}

如果这不起作用，您也可以尝试：

Google Maps API位置现在可以使用，即使有听众，您也可以使用它，例如：

private GoogleMap.OnMyLocationChangeListener myLocationChangeListener = new GoogleMap.OnMyLocationChangeListener() {
    @Override
    public void onMyLocationChange(Location location) {
        LatLng loc = new LatLng(location.getLatitude(), 16.0f));
    }
};

我建议reading the following了解更多信息。

Google地图上的当前位置

1 个答案: