如何更改片段上的地图视图？

Question

我正在使用mapbox api开发一个应用程序。在地图上，当用户点击菜单上的地图项时，一个片段将会打开。后面的用户可能想要更改地图视图样式，例如卫星，黑暗，祖母绿或街道视图。用户可以在操作栏上选择地图样式。我在主要活动上实施了我的操作栏。当地图片段上的用户选择地图样式并且变量来到主要活动中处理的片段时。这个变量是地图样式的字符串。现在我想更改地图视图样式而不重新创建地图片段。你可以就这个问题提出建议吗？

public class GeoMapFragment extends Fragment implements OnMapReadyCallback { 

    public MapView mapView = null; 
    private MapboxMap mapboxMap; 
    public String mapViewSelectedItem ; 

    private static final int PERMISSIONS_LOCATION = 0; 

    public GeoMapFragment() { 
     // Required empty public constructor 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 


    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View view = inflater.inflate(R.layout.fragment_geomap, container, false); 


     mapView = (MapView)view.findViewById(R.id.mapview); 
     mapView.onCreate(savedInstanceState); 
     mapView.getMapAsync(this); 

     // Inflate the layout for this fragment 
     return view; 
    } 

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

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

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

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

    /** 
    * Dispatch onPause() to fragments. 
    */ 
    @Override 
    public void onPause() { 
     super.onPause(); 
     mapView.onPause(); 
    } 


    @Override 
    public void onMapReady(MapboxMap map) { 

     mapboxMap = map; 
     mapboxMap.setStyle(Style.DARK); 
     mapboxMap.moveCamera(CameraUpdateFactory.newLatLng(new LatLng(0, 0))); 

     // Show user location (purposely not in follow mode) 
     if ((ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) || 
       (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)) { 
      ActivityCompat.requestPermissions(getActivity(), new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSIONS_LOCATION); 
     } else { 
      mapboxMap.setMyLocationEnabled(true); 
     } 

     // TODO - mv.loadFromGeoJSONURL("https://gist.githubusercontent.com/tmcw/10307131/raw/21c0a20312a2833afeee3b46028c3ed0e9756d4c/map.geojson"); 
     mapboxMap.addMarker(new MarkerOptions().title("Edinburgh").snippet("Scotland").position(new LatLng(55.94629, -3.20777))); 
     mapboxMap.addMarker(new MarkerOptions().title("Stockholm").snippet("Sweden").position(new LatLng(59.32995, 18.06461))); 
     mapboxMap.addMarker(new MarkerOptions().title("Prague").snippet("Czech Republic").position(new LatLng(50.08734, 14.42112))); 
     mapboxMap.addMarker(new MarkerOptions().title("Athens").snippet("Greece").position(new LatLng(37.97885, 23.71399))); 
     mapboxMap.addMarker(new MarkerOptions().title("Tokyo").snippet("Japan").position(new LatLng(35.70247, 139.71588))); 
     mapboxMap.addMarker(new MarkerOptions().title("Ayacucho").snippet("Peru").position(new LatLng(-13.16658, -74.21608))); 
     mapboxMap.addMarker(new MarkerOptions().title("Nairobi").snippet("Kenya").position(new LatLng(-1.26676, 36.83372))); 
     mapboxMap.addMarker(new MarkerOptions().title("Canberra").snippet("Australia").position(new LatLng(-35.30952, 149.12430))); 

    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
     switch (requestCode) { 
      case PERMISSIONS_LOCATION: { 
       if (grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
        mapboxMap.setMyLocationEnabled(true); 
       } 
      } 
     } 
    } 

Answer 1

你的地图片段应该有一个getMapAsync()调用，你可以改变它的风格。下面有你如何能做到这一点粗略的例子：

private MapboxMap map; 

... 

mapFragment.getMapAsync(new OnMapReadyCallback() { 
     @Override 
     public void onMapReady(final MapboxMap mapboxMap) { 

      map = mapboxMap; 

     } 
    }); 

... 

// Wherever you implemented receiving the style string from MainActivity you can include this: 

map.setStyleUrl(<style url>); 

如果这不适合你，请让我知道你是如何准确地创建地图片段。目前，该SDK包括一个片段已经，您可以设置像这样：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    SupportMapFragment mapFragment; 
    if (savedInstanceState == null) { 
     FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); 

     LatLng patagonia = new LatLng(-52.6885, -70.1395); 

     MapboxMapOptions options = new MapboxMapOptions(); 
     options.accessToken("<your access token here>"); 
     options.styleUrl(Style.SATELLITE); 
     options.camera(new CameraPosition.Builder() 
       .target(patagonia) 
       .zoom(9) 
       .build()); 

     mapFragment = SupportMapFragment.newInstance(options); 

     transaction.add(R.id.container, mapFragment, "mapFragment"); 
     transaction.commit(); 
    } else { 
     mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentByTag("mapFragment"); 
    } 

    mapFragment.getMapAsync(new OnMapReadyCallback() { 
     @Override 
     public void onMapReady(final MapboxMap mapboxMap) { 

      map = mapboxMap; 

     } 
    }); 
} 

如果你这样做了，你可以很容易地改变地图的风格就像我上面说的。

希望这可以帮到你！