谷歌地图上的片段

Question

我正在尝试在片段活动中设置Google地图，但是每当我尝试移至地图片段时，应用程序都会崩溃

日志猫

FATAL EXCEPTION: main
 Process: com.example.layouts2, PID: 6254
 android.view.InflateException: Binary XML file line #16: Error inflating class fragment
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
    at com.example.layouts2.FragmentC.onCreateView(FragmentC.java:29)
    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)

这是我的地图课。

public class FragmentC  extends Fragment{
    MapView mMapView;
    private GoogleMap googleMap;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // inflat and return the layout
        View v = inflater.inflate(R.layout.frag4, container,
                false);
        mMapView = (MapView) v.findViewById(R.id.map);
        mMapView.onCreate(savedInstanceState);

        mMapView.onResume();// needed to get the map to display immediately

        try {
            MapsInitializer.initialize(getActivity().getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }

        googleMap = mMapView.getMap();
        // latitude and longitude
        double latitude = 17.385044;
        double longitude = 78.486671;

        // create marker
        MarkerOptions marker = new MarkerOptions().position(
                new LatLng(latitude, longitude)).title("Hello Maps");

        // Changing marker icon
        marker.icon(BitmapDescriptorFactory
                .defaultMarker(BitmapDescriptorFactory.HUE_ROSE));

        // adding marker
        googleMap.addMarker(marker);
        CameraPosition cameraPosition = new CameraPosition.Builder()
                .target(new LatLng(17.385044, 78.486671)).zoom(12).build();
        googleMap.animateCamera(CameraUpdateFactory
                .newCameraPosition(cameraPosition));

        // Perform any camera updates here
        return v;
    }

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

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

    @Override
    public void onDestroy() {
        super.onDestroyView();
       // Log.d(TAG, "onDestroyView");

        Fragment f = getActivity()
                .getSupportFragmentManager().findFragmentById(R.id.map);
        if (f != null) {
            getActivity().getSupportFragmentManager()
            .beginTransaction().remove(f).commit();
        }
    }

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

布局文件

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.layouts.MainActivity$PlaceholderFragment" >

   <FrameLayout
            android:id="@+id/map"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

</RelativeLayout>

我已经导入了Google Play服务库，并且提到了很多SO帖子。 我应该怎么做才能使其正常工作？

Answer 1

不推荐使用MapView.getMap() ，并且可能以某种方式返回null。 因此，您应该改用MapView.getMapAsync (OnMapReadyCallback callback) ，在这里修改您的代码：

public class FragmentC  extends Fragment implements OnMapReadyCallback{
MapView mMapView;
private GoogleMap googleMap;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // inflat and return the layout
    View v = inflater.inflate(R.layout.frag4, container,
            false);
    mMapView = (MapView) v.findViewById(R.id.map);
    mMapView.onCreate(savedInstanceState);

    mMapView.onResume();// needed to get the map to display immediately

    try {
        MapsInitializer.initialize(getActivity().getApplicationContext());
    } catch (Exception e) {
        e.printStackTrace();
    }

    mMapView.getMapAsync(this);
    //original codes here moved to onMapReady method


    // Perform any camera updates here
    return v;
}

//new method
@Override
public void onMapReady(GoogleMap gMap) 
{

    googleMap = gMap;

     // latitude and longitude
    double latitude = 17.385044;
    double longitude = 78.486671;

    // create marker
    MarkerOptions marker = new MarkerOptions().position(
            new LatLng(latitude, longitude)).title("Hello Maps");

    // Changing marker icon
    marker.icon(BitmapDescriptorFactory
            .defaultMarker(BitmapDescriptorFactory.HUE_ROSE));

    // adding marker
    googleMap.addMarker(marker);
    CameraPosition cameraPosition = new CameraPosition.Builder()
            .target(new LatLng(17.385044, 78.486671)).zoom(12).build();
    googleMap.animateCamera(CameraUpdateFactory
            .newCameraPosition(cameraPosition));

}


//following codes no change
@Override
public void onResume() {
    super.onResume();
    mMapView.onResume();
}

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

@Override
public void onDestroy() {
    super.onDestroyView();
   // Log.d(TAG, "onDestroyView");

    Fragment f = getActivity()
            .getSupportFragmentManager().findFragmentById(R.id.map);
    if (f != null) {
        getActivity().getSupportFragmentManager()
        .beginTransaction().remove(f).commit();
    }
}

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

希望对您有所帮助！