我可以看到地图，但不会放大当前位置。 try-catch块中的代码中断，可以看到Google Play Services missing !。
**这就是发生碰撞的地方**
map = mapFragment.getMap();
以下完整代码：
public class MyMapFragment extends Fragment implements
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener {
GoogleMap map;
LatLng latlng;
private LocationRequest lr;
private LocationServices lc; //was LocationClient
MapFragment mapFragment;
//ImageView iv;
private static View view;
@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_map, container, false);
SupportMapFragment mMapFragment = SupportMapFragment.newInstance();
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.add(R.id.map_container, mMapFragment).commit();
mapFragment = ((MapFragment) this.getActivity()
.getFragmentManager().findFragmentById(R.id.map_container));
map = mapFragment.getMap(); **THIS IS WHERE THE CRASH HAPPENS **
map.getUiSettings().setAllGesturesEnabled(false);
map.getUiSettings().setMyLocationButtonEnabled(false);
if (ContextCompat.checkSelfPermission(getActivity(),
Manifest.permission.ACCESS_FINE_LOCATION) // this might need massaged to 'android.permission.USE_FINGERPRINT'
!= PackageManager.PERMISSION_GRANTED) {
map.setMyLocationEnabled(true);
} else {
map.setMyLocationEnabled(false);
}
map.getUiSettings().setZoomControlsEnabled(false);
MapsInitializer.initialize(getActivity());
Toast.makeText(getActivity(), "Printing from MyMapFragment", Toast.LENGTH_LONG).show();
return view;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
Log.d("Attach", "on attach");
}
@Override
public void onDetach() {
super.onDetach();
}
@Override
public void onConnected(@Nullable Bundle bundle) {
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
}
Android XML文件：R.layout.fragment_map.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
堆栈跟踪：
FATAL EXCEPTION: main
Process: com.mavdev.gunfreebusinesses, PID: 29988
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mavdev.gunfreebusinesses/com.mavdev.gunfreebusinesses.activities.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.maps.GoogleMap com.google.android.gms.maps.MapFragment.getMap()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2339)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413)
at android.app.ActivityThread.access$800(ActivityThread.java:155)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.maps.GoogleMap com.google.android.gms.maps.MapFragment.getMap()' on a null object reference
at com.mavdev.gunfreebusinesses.fragments.MyMapFragment.onCreateView(MyMapFragment.java:77)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:330)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:547)
at com.mavdev.gunfreebusinesses.activities.MainActivity.onStart(MainActivity.java:385)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1259)
at android.app.Activity.performStart(Activity.java:6026)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2302)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2413)
at android.app.ActivityThread.access$800(ActivityThread.java:155)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
答案 0 :(得分：1)
Xml代码
<fragment android:id="@+id/map_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.MapFragment"/>
使用
GoogleMap map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map_container)).getMap();
而不是
map = mapFragment.getMap();
在Activity java代码
中private MapFragment getMapFragment() {
FragmentManager fm = null;
Log.d(TAG, "sdk: " + Build.VERSION.SDK_INT);
Log.d(TAG, "release: " + Build.VERSION.RELEASE);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
// using getFragmentManager
fm = getFragmentManager();
} else {
//using getChildFragmentManager
fm = getChildFragmentManager();
}
return (MapFragment) fm.findFragmentById(R.id.map_container);
}