获取用户位置并将其显示在地图上（对我而言未显示的地图）

Question

我正在做一个大学项目，我必须在OSM地图中显示用户位置，并使用Retrofit API中的数据标记。 我现在不担心api数据，但是我的地图没有显示。

我所得到的就是这个：MainMap 这里的坐标是随机的。

我的地图活动：

    public class MapaPrincipal extends AppCompatActivity implements LocationListener {
    private MapView osm;
    private MapController mc;
    private LocationManager locationManager;

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mapa_principal);

        osm = (MapView) findViewById(R.id.mapView);
        osm.setTileSource(TileSourceFactory.MAPNIK);
        osm.setBuiltInZoomControls(true);
        osm.setMultiTouchControls(true);

        mc = (MapController) osm.getController();

        GeoPoint center = new GeoPoint(14.1, 19.2);

        mc.setZoom(12);
        mc.animateTo(center);

        addMarker(center);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    Activity#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 Activity#requestPermissions for more details.
            return;
        }
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
    }

    public void addMarker(GeoPoint center){
        Marker marker = new Marker(osm);
        marker.setPosition(center);
        marker.setAnchor(Marker.ANCHOR_CENTER, Marker.ANCHOR_BOTTOM);


        osm.getOverlays().clear();
        osm.getOverlays().add(marker);
        osm.invalidate();
    }

    @Override
    public void onLocationChanged(Location location) {
        GeoPoint center = new GeoPoint(location.getLatitude(),location.getLongitude());

        mc.animateTo(center);
        addMarker(center);
    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onProviderDisabled(String s) {

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(locationManager!=null){
            locationManager.removeUpdates(this);
        }
    }
}

我的地图布局：

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <org.osmdroid.views.MapView
        android:id="@+id/mapView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

</LinearLayout>

Android清单：

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="pt.ipp.estg.osm">

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

    <application
        android:usesCleartextTraffic="true"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".SignUpActivity" />
        <activity android:name=".MapaPrincipal" />
    </application>

</manifest>

有人可以帮我吗？