无法在地图上获取当前位置按钮

Question

无法访问用户的当前位置.. ... 。

package com.example.admin.myapplication;

/**
 * Created by Admin on 21-Nov-16.
 */
public class Map extends AppCompatActivity implements OnMapReadyCallback {


    GoogleMap mGoogleMap;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (googleServicesAvailable()) {
            requestWindowFeature(Window.FEATURE_NO_TITLE);
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
            setContentView(R.layout.map);
            Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);

            initMap();
        } else {
            //No Google Maps Layout
        }
    }

    private void initMap() {
        MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.mapfragment);
        mapFragment.getMapAsync(this);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.map_type_menu, menu);
        return true;
    }

    public boolean googleServicesAvailable() {
        GoogleApiAvailability api = GoogleApiAvailability.getInstance();
        int isAvailable = api.isGooglePlayServicesAvailable(this);
        if (isAvailable == ConnectionResult.SUCCESS) {
            return true;
        } else if (api.isUserResolvableError(isAvailable)) {
            Dialog dialog = api.getErrorDialog(this, isAvailable, 0);
            dialog.show();
        } else {
            Toast.makeText(this, "Can't connect to play services", Toast.LENGTH_LONG).show();
        }
        return false;
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;
        mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        goToLocationZoom(31.773214,76.984563,16);


        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;
        }
        mGoogleMap.setMyLocationEnabled(true);

    }

    private void goToLocationZoom(double lat, double lng, float zoom) {
        LatLng ll = new LatLng(lat, lng);
        CameraUpdate upadatezoom = CameraUpdateFactory.newLatLngZoom(ll, zoom);
        mGoogleMap.moveCamera(upadatezoom);
    }


}