因为我在我的应用程序中使用 MAPBOX。我不知道如何获得当前的纬度和经度。我用这种方式获取当前位置。但是它显示空对象引用。请帮助我解决我的问题

mapView = (MapView)view.findViewById(R.id.mapView);
mapView.setStyleUrl(Style.MAPBOX_STREETS);
mapView.onCreate(savedInstanceState);

//Add a mapBoxMap
mapView.getMapAsync(new OnMapReadyCallback() {
    @Override
    public void onMapReady(MapboxMap mapboxMap) {
        mapboxMap.setMyLocationEnabled(true);
        // Set the origin waypoint to the devices location
        Position origin = Position.fromCoordinates(
            mapboxMap.getMyLocation().getLongitude(),
            mapboxMap.getMyLocation().getLatitude()
        );

        Log.i("RR","mapboxMap.getMyLocation();"+origin);
        // Log.i("RR","mapboxMap.getMyLocation();"+mapboxMap.getMyLocation().getLongitude());
        mapboxMap.getUiSettings().setZoomControlsEnabled(true);
        mapboxMap.getUiSettings().setZoomGesturesEnabled(true);
        mapboxMap.getUiSettings().setScrollGesturesEnabled(true);
        mapboxMap.getUiSettings().setAllGesturesEnabled(true);
    }
});

最佳答案

经过 1 天的搜索，我得到了结果 这是获取 MapBox 用户当前位置的完整代码。 主要 Activity :

import android.Manifest;
import android.annotation.SuppressLint;
import android.content.pm.PackageManager;
import android.location.Location;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.mapbox.android.core.location.LocationEngine;
import com.mapbox.android.core.location.LocationEngineListener;
import com.mapbox.android.core.location.LocationEnginePriority;
import com.mapbox.android.core.location.LocationEngineProvider;
import com.mapbox.android.core.permissions.PermissionsListener;
import com.mapbox.android.core.permissions.PermissionsManager;
import com.mapbox.mapboxsdk.Mapbox;
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory;
import com.mapbox.mapboxsdk.geometry.LatLng;
import com.mapbox.mapboxsdk.maps.MapView;
import com.mapbox.mapboxsdk.maps.MapboxMap;
import com.mapbox.mapboxsdk.maps.OnMapReadyCallback;
import com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerPlugin;
import com.mapbox.mapboxsdk.plugins.locationlayer.modes.CameraMode;
import com.mapbox.mapboxsdk.plugins.locationlayer.modes.RenderMode;

import java.util.List;

public class Main2Activity extends AppCompatActivity implements OnMapReadyCallback, LocationEngineListener, PermissionsListener {
    private MapView mapView;
    private MapboxMap map;
    LocationEngine locationEngine;
    LocationLayerPlugin locationLayerPlugin;
    PermissionsManager permissionsManager;
    Location originLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Mapbox.getInstance(this, "YOUR_MAPBOX_KEY");
        setContentView(R.layout.activity_main2);
        mapView = (MapView) findViewById(R.id.mapView);
        mapView.onCreate(savedInstanceState);
        mapView.getMapAsync(this);
    }

    @Override
    public void onMapReady(MapboxMap mapboxMap) {
       /* LocationPluginActivity.this.map = map;
        enableLocationPlugin();*/
        map = mapboxMap;
        locationEnable();
        mapboxMap.getUiSettings().setZoomControlsEnabled(true);
        mapboxMap.getUiSettings().setZoomGesturesEnabled(true);
        mapboxMap.getUiSettings().setScrollGesturesEnabled(true);
        mapboxMap.getUiSettings().setAllGesturesEnabled(true);
    }

    void locationEnable() {
        if (PermissionsManager.areLocationPermissionsGranted(this)) {
            intialLocationEngine();
            intializLocationLayer();
        } else {
            permissionsManager = new PermissionsManager(this);
            permissionsManager.requestLocationPermissions(this);
        }
    }

    void intialLocationEngine() {
        locationEngine = new LocationEngineProvider(this).obtainBestLocationEngineAvailable();
        locationEngine.setPriority(LocationEnginePriority.HIGH_ACCURACY);
        locationEngine.activate();
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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 lastLocation = locationEngine.getLastLocation();
        if (lastLocation != null) {
            originLayout = lastLocation;
            setCamerpostion(lastLocation);
        } else {
            locationEngine.addLocationEngineListener(this);
        }

    }

    void intializLocationLayer() {
        locationLayerPlugin = new LocationLayerPlugin(mapView, map, locationEngine);
        locationLayerPlugin.setLocationLayerEnabled(true);
        locationLayerPlugin.setCameraMode(CameraMode.TRACKING);
        locationLayerPlugin.setRenderMode(RenderMode.NORMAL);
    }

    void setCamerpostion(Location camerpostion) {
        map.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(camerpostion.getLatitude(), camerpostion.getLongitude()), 13.0));
    }

    @Override
    public void onConnected() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        locationEngine.requestLocationUpdates();
    }

    @Override
    public void onLocationChanged(Location location) {
        if (location != null) {
            originLayout = location;
            setCamerpostion(location);
        }
    }

    @Override
    public void onExplanationNeeded(List<String> permissionsToExplain) {

    }

    @Override
    public void onPermissionResult(boolean granted) {
        if (granted) {
            locationEnable();
        }

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        permissionsManager.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
    @SuppressWarnings("MissingPermission")
    @Override
    public void onStart() {
        super.onStart();
        if (locationEngine != null)
           locationEngine.requestLocationUpdates();
        mapView.onStart();
    }

    @Override
    public void onResume() {
        super.onResume();
        mapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mapView.onPause();
    }

    @Override
    public void onStop() {
        super.onStop();
        mapView.onStop();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mapView.onLowMemory();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (locationEngine!=null)
        {
            locationEngine.deactivate();
        }        mapView.onDestroy();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        mapView.onSaveInstanceState(outState);
    }
}

这是 Xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.joltatech.selfmadmap.Main2Activity">

    <com.mapbox.mapboxsdk.maps.MapView
        android:id="@+id/mapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:mapbox_cameraTargetLat="40.73581"
        app:mapbox_cameraTargetLng="-73.99155"
        app:mapbox_styleUrl="@string/mapbox_style_satellite_streets"
        app:mapbox_cameraZoom="11"/>
</RelativeLayout>

这是 Gradle 文件:

implementation 'com.mapbox.mapboxsdk:mapbox-android-sdk:6.3.0'
implementation 'com.mapbox.mapboxsdk:mapbox-android-plugin-locationlayer:0.6.0'

并在项目级 Gradle 中使用:

jcenter()
mavenCentral()

关于android - 如何在android中的MAPBOX中获取当前位置，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47258922/