Question

我发现很多线程都与在片段中添加地图片段有关。但他们并没有帮助我解决我的问题。我试图将一个地图片段添加到片段中。但我得到Null指针异常如下：

11-25 10:19:55.222    9101-9101/com.uma.mobile E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.uma.mobile, PID: 9101
java.lang.NullPointerException
        at com.uma.mobile.subview.ShopDetails.<init>(ShopDetails.java:122)
        at com.uma.mobile.activity.Shop.onCreateView(Shop.java:119)
        at android.app.Fragment.performCreateView(Fragment.java:1700)
        at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:890)
        at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
        at android.app.BackStackRecord.run(BackStackRecord.java:684)
        at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
        at android.app.FragmentManagerImpl$1.run(FragmentManager.java:443)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4998)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
        at dalvik.system.NativeStart.main(Native Method)

其中Shop.java扩展Fragment，ShopDetails扩展了RelativeLayout，其中包含mapFragement。

shop_details.xml：

<RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:id="@+id/mapTile"
            android:layout_marginTop="10dp"
            android:padding="10dp"
            android:background="@drawable/grey_gradient_rounded"
            android:layout_below="@+id/description">


            <RelativeLayout
                android:id="@+id/mapViewContainer"
                android:layout_width="100dp"
                android:layout_height="wrap_content"
                android:layout_alignTop="@+id/nearestLocation"
                android:layout_alignBottom="@+id/tapToView" />
                <!--<fragment xmlns:android="http://schemas.android.com/apk/res/android"-->
                    <!--android:id="@+id/mapView"-->
                    <!--android:layout_width="100dp"-->
                    <!--android:layout_height="wrap_content"-->
                    <!--android:name="com.google.android.gms.maps.MapFragment"/>-->

这就是我添加地图片段的方式

mapFragment = new MapFragment();
    FragmentTransaction transaction=  fm.findFragmentByTag("SHOPS").getChildFragmentManager().beginTransaction();
    transaction.add(R.id.mapViewContainer,mapFragment,"MAP_FRAG").commit();

这是我得到例外的地方：

try {

                    MapsInitializer.initialize(activity);
                    mapFragment.getMap().getUiSettings().setZoomControlsEnabled(false);
                    LatLng position = new LatLng(loc._latitude, loc._longitude);
                    MarkerOptions markerOptions = new MarkerOptions()
                            .position(position)
                            .icon(BitmapDescriptorFactory.fromResource(R.drawable.arrow_pin2x));
                    mapFragment.getMap().addMarker(markerOptions);
                    mapFragment.getMap().moveCamera(CameraUpdateFactory.newLatLngZoom(position, 14));
                } catch (GooglePlayServicesNotAvailableException e) {
                    e.printStackTrace();
                    fm.beginTransaction().hide(mapFragment).commit();
                }
                            .icon(BitmapDescriptorFactory.fromResource(R.drawable.arrow_pin2x));
                    map.addMarker(markerOptions);
                    map.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 14));

mapFragment.getMap（）。getUiSettings（）

Answer 1

你应该在片段中使用mapview它也支持map v2。请参阅此https://developers.google.com/maps/documentation/android/reference/com/google/android/gms/maps/MapView

尝试一下它会起作用。

public class MyMapFragment extends Fragment {

    private MapView mMapView;
    private GoogleMap mMap;
    private Bundle mBundle;

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

        try {
            MapsInitializer.initialize(getActivity());
        } catch (GooglePlayServicesNotAvailableException e) {
            // TODO handle this situation
        }

        mMapView = (MapView) inflatedView.findViewById(R.id.map);
        mMapView.onCreate(mBundle);
        setUpMapIfNeeded(inflatedView);

        return inflatedView;
    }

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

    private void setUpMapIfNeeded(View inflatedView) {
        if (mMap == null) {
            mMap = ((MapView) inflatedView.findViewById(R.id.map)).getMap();
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
    }

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

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

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

这是相应的res / layout / map_fragment.xml：

<?xml version="1.0" encoding="utf-8"?>
<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" />
</RelativeLayout>

如果您的布局中只有一个元素，则可以省略RelativeLayout（并将xmlns声明移动到新的根元素，在本例中为com.google.android.gms.maps.MapView）

片段中的Android MapFragment

1 个答案: