导航抽屉和谷歌地图

Question

我尝试做一个显示带有导航抽屉的地图的应用程序。

如果我运行包含 MapsActivity 的 MainActivity（带有导航抽屉的 Activity），它只会显示地图并且不会在地图上放置标记，但如果我只运行 MapsActivity，则会放置标记。

如果我运行 MainActivity，MapsActivity 中的代码似乎不会运行，但为什么呢？我能做什么？

代码如下：

地图活动：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

private GoogleMap mMap;
private String providerId = LocationManager.GPS_PROVIDER;
private Geocoder geo = null;
private LocationManager locationManager = null;

@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);
}

@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));
}
// Other methods
}

主活动：

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {

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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}
//Other methods
}

布局： activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>    
<android.support.v4.widget.DrawerLayout
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:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true" tools:openDrawer="start">

<include layout="@layout/activity_maps"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<include layout="@layout/app_bar_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_main"
    app:menu="@menu/activity_main_drawer" />

</android.support.v4.widget.DrawerLayout>

布局：activity_maps.xml：

<RelativeLayout 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">

<fragment 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:id="@+id/map"
    tools:context=".MapsFragment"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    tools:layout="@layout/activity_maps" />

</RelativeLayout>

Answer 1

您不能在另一个 Activity（例如 MainActivity）中执行 Activity（例如 MapActivity）。应该改用 MapFragment。

这里是code，你可以看看。您也可以在我的 github 上尝试project，这不是 Navigation Draw 中的 mapFragment，但可以让您了解 MapFragment 的工作原理。

MapFragment 的示例代码：

public class MapFragment extends Fragment {

    private SupportMapFragment mMapView;

    public static MapFragment newInstance(String param1, String param2) {
        MapFragment fragment = new MapFragment();
        return fragment;
    }

    MapView mapView;
    GoogleMap map;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_map, container, false);
        // Gets the MapView from the XML layout and creates it

        MapsInitializer.initialize(getActivity());


        switch (GooglePlayServicesUtil.isGooglePlayServicesAvailable(getActivity())) {
            case ConnectionResult.SUCCESS:
                Toast.makeText(getActivity(), "SUCCESS", Toast.LENGTH_SHORT).show();
                mapView = (MapView) v.findViewById(R.id.map);
                mapView.onCreate(savedInstanceState);
                // Gets to GoogleMap from the MapView and does initialization stuff
                if (mapView != null) {
                    map = mapView.getMap();
                    map.getUiSettings().setMyLocationButtonEnabled(false);
                    map.setMyLocationEnabled(true);
                    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(43.1, -87.9), 10);
                    map.animateCamera(cameraUpdate);
                }
                break;
            case ConnectionResult.SERVICE_MISSING:
                Toast.makeText(getActivity(), "SERVICE MISSING", Toast.LENGTH_SHORT).show();
                break;
            case ConnectionResult.SERVICE_VERSION_UPDATE_REQUIRED:
                Toast.makeText(getActivity(), "UPDATE REQUIRED", Toast.LENGTH_SHORT).show();
                break;
            default:
                Toast.makeText(getActivity(), GooglePlayServicesUtil.isGooglePlayServicesAvailable(getActivity()), Toast.LENGTH_SHORT).show();
        }

        // Updates the location and zoom of the MapView

        LatLng sydney = new LatLng(-33.867, 151.206);

        map.setMyLocationEnabled(true);
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(sydney, 13));

        map.addMarker(new MarkerOptions()
                .title("Sydney")
                .snippet("The most populous city in Australia.")
                .position(sydney));

        return v;
    }

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

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

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

它的布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent">

    <com.google.android.gms.maps.MapView
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:name="com.bojie.materialtest.fragments.UpcomingFragment"/>

</RelativeLayout>