谷歌地图片段中的片段无法操作我的地图

Question

我试图在另一个片段中显示一个谷歌地图片段，但是我不能操纵地图，我已经把我看到的所有步骤都留档了，但是我不能操纵我的地图。

XML代码：

<FrameLayout 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"
tools:context=".FragmentoPrincipalUsuario">

<!-- TODO: Update blank fragment layout -->


<LinearLayout
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal|top">

    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="391dp"
        class="com.google.android.gms.maps.MapFragment"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="60dp" />

</LinearLayout>

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="149dp"
    android:layout_gravity="center_horizontal|bottom">

    <Button
        android:layout_width="117dp"
        android:layout_height="wrap_content"
        android:text="pedir taxi"
        android:id="@+id/pedirTaxi"
        android:layout_gravity="center_horizontal" />

</LinearLayout>

类片段代码：

public class FragmentoPrincipalUsuario extends Fragment implements OnMapReadyCallback  {

    private OnFragmentInteractionListener mListener;
    private List<ParseUser> mChoferes;
    private ParseUser       mUsuarioActual;
    private Button          mPedido;
    private GoogleMap map;


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


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        //conseguir usuario actual
       // mUsuarioActual = ParseUser.getCurrentUser();

        View x = inflater.inflate(R.layout.fragmento_principal_usuario, container, false);




        //evento boton pedir taxi
        mPedido.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                ParseQuery<ParseUser> query = ParseUser.getQuery();
                query.whereEqualTo("tipoUsuario", "chofer");
                query.findInBackground(new FindCallback<ParseUser>() {
                    public void done(List<ParseUser> choferes, com.parse.ParseException e) {
                        if (e == null) {

                            mChoferes = choferes;
                            String nombreChofer;

                            for (ParseUser chofer : mChoferes) {

                                nombreChofer = chofer.getUsername();

                                ParseObject gameScore = new ParseObject("Viaje");
                                gameScore.put("cliente", "hola");
                                gameScore.put("chofer", nombreChofer);
                                gameScore.put("tomado", false);
                                gameScore.saveInBackground();


                            }
                        } else {
                            // Something went wrong.
                        }
                    }
                });

            }
        });



        // Inflate the layout for this fragment
        return x;

    }


    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);

        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    @Override
    public void onMapReady(GoogleMap map) {
        LatLng sydney = new LatLng(-27.7933121, -64.2574857);
        map.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        map.moveCamera(CameraUpdateFactory.newLatLng(sydney));

    }


    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p/>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }

主要活动类别代码：

public class DrawerPrincipal extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener,FragmentoPrincipalUsuario.OnFragmentInteractionListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_drawer_principal);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    //cargar fragment principal usuario


    Fragment fragmento= null;
    fragmento = new FragmentoPrincipalUsuario();
   getSupportFragmentManager().beginTransaction()
           .replace(R.id.content_main, fragmento)
           .commit();



    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);



}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.pantalla_principal_usuario, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.cuenta) {
        // Handle the camera action
    } else if (id == R.id.historial_viajes) {

    } else if (id == R.id.contacto) {

    } else if (id == R.id.compartir) {

    } else if (id == R.id.version) {

    } else if (id == R.id.salir) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onFragmentInteraction(Uri uri) {

}

}

在调用getMapAsync（）后，编辑以下堆栈跟踪：

空指针错误：

12-18 19:51:50.056 11265-11265/ar.com.taxiexpress.taxiexpressE/AndroidRuntime： FATAL EXCEPTION： mainjava.lang.RuntimeExcture：无法启动活动ComponentInfo{ar.com.taxiexpress.taxiexpress/ar.com.taxiexpress.taxiexpress.DrawerPrincipal}：java.lang.在android.app.ActivityThread.perform启动活动（活动Thread.java:2180）在android.app.活动Thread.handle启动活动（活动Thread.java:2230）在android.app.活动Thread.access600美元（活动Thread.java:141）在android.app.活动线程$H. handleMessage（ActivityThread.java:1234）在android.os.Handler.dispatchMessage（Handler.java:99）在android.os.Looper.loop（Loop. java： 137）在android. app.ActivityThread. main（ActivityThread. java： 5041）在java. lang.反射。方法。方法调用（方法. java： 511）在com. android. interal. os。ZygoteInit$method odAndArgsCaller. run（ZygoteInit. java： 793）在com. android. interal. os。在dalvik. system上的ZygoteInit. main（ZygoteInit. java： 560）。NativeStart. main（本地方法）引起：java. lang.在ar. com. taxiExpress. taxiExpress.在android. support. v4. app.上创建视图（FragmentoPrindalStuario. java： 61）。Fragment. performCreateView（Fragment. java： 1962）在android. support. v4. app.FragmentManagerImp. moveToState（FragmentManager. java： 1067）at android. support. v4. app.FragmentManagerImp. moveToState（FragmentManager. java： 1248）at android. support. v4. app.在android. support. v4. app上运行（BackStackRecord. java： 738）。在android. support. v4. app上的FragmentManagerImp. expendingActions（FragmentManager. java： 1613）。在android. support. v4. app上的FragmentController. expendingActions（FragmentController. java： 330）。在android. app. onStart（FragmentActive. java： 547）。在android. app.在android. app.在android. app上的ActivityThread. perform解雇活动（ActivityThread. java： 2153）。在android. app.在android. app访问600美元（ActivityThread. java： 141）。ActivityThread$H. handleMessage（ActivityThread. java： 1234）at android. os.在android. os.在android. app.ActivityThread. main（ActivityThread. java： 5041）在java. lang.反射。方法。方法调用（方法. java： 511）在com. android. interal. os。ZygoteInit$method odAndArgsCaller. run（ZygoteInit. java： 793）在com. android. interal. os。在dalvik. system上的ZygoteInit. main（ZygoteInit. java： 560）。NativeStart. main（本机方法）

Answer 1

看起来主要的问题是您没有调用getMapAsync（）。

由于您使用的是片段内部的嵌套支持MapFra402，因此您需要使用getChildFragmentManager（）来获取Map碎片，然后调用getMapAsync（）。

SupportMapFragment mapFragment = ((SupportMapFragment) getChildFragmentManager()
            .findFragmentById(R.id.map));
mapFragment.getMapAsync(this);

但是，虽然这样做可行，但最好让片段扩展SupportMapFragment，这样就不需要嵌套片段：

public class MyMapFragment extends SupportMapFragment 
                                    implements OnMapReadyCallback {

    private GoogleMap mMap;
    private Marker marker;


    public MyMapFragment () {
    }

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

        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {

        if (mMap == null) {

            getMapAsync(this);
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        mMap = googleMap;
        setUpMap();
    }

    private void setUpMap() {

        mMap.setMyLocationEnabled(true);
        mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        mMap.getUiSettings().setMapToolbarEnabled(false);


        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

            @Override
            public void onMapClick(LatLng point) {

                //remove previously placed Marker
                if (marker != null) {
                    marker.remove();
                }

                //place marker where user just clicked
                marker = mMap.addMarker(new MarkerOptions().position(point).title("Marker")
                        .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)));

            }
        });

    }

}