在 Fragment 的地图中检测当前位置时遇到问题
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【中文标题】在 Fragment 的地图中检测当前位置时遇到问题【英文标题】：Trouble detecting current location in a map in Fragment 【发布时间】：2016-04-13 23:17:42 【问题描述】：我可以看到地图，但无法放大当前位置。代码在 try-catch 块中中断，并看到 Google Play Services missing !。
**这是发生崩溃的地方**
map = mapFragment.getMap();
完整代码如下：
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_
android:layout_
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_
android:layout_ />
</LinearLayout>
堆栈跟踪：
FATAL EXCEPTION: main
Process: com.mavdev.gunfreebusinesses, PID: 29988
java.lang.RuntimeException: Unable to start activity ComponentInfocom.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)
【问题讨论】：
检查我的编辑答案 您是否尝试过使用getMapAsync？据我所知，getMap 现在已被弃用
【参考方案1】：
Xml 代码
<fragment android:id="@+id/map_container"
android:layout_
android:layout_
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);
【讨论】：
嗨@sasikumar - 我在片段本身中收到此错误。我正在片段的 onCreateView 中尝试这个：i.imgur.com/m2uAaQY.jpg以上是关于在 Fragment 的地图中检测当前位置时遇到问题的主要内容，如果未能解决你的问题，请参考以下文章