当我尝试这样做时，我得到了一个nullpointerexception：
mapview.onCreate(savedInstanceState);
这是我的代码：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.home_fragment, container, false);
setRetainInstance(true);
setHasOptionsMenu(true);
try {
MapsInitializer.initialize(getActivity().getApplicationContext());
} catch (Exception e) {
e.printStackTrace();
}
mapView = (MapView) rootView.findViewById(R.id.map);
mapView.onCreate(savedInstanceState);
mapView.onResume();
.........
LOGCAT：
01-14 11:36:40.744 27070-27070/? E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.maptest/com.test.maptest.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2343)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
at android.app.ActivityThread.access$600(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5403)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.google.maps.api.android.lib6.gmm6.m.ad.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.c.h.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.c.y.a(Unknown Source)
at com.google.maps.api.android.lib6.e.bd.a(Unknown Source)
at com.google.maps.api.android.lib6.e.ev.a(Unknown Source)
at com.google.maps.api.android.lib6.e.af.a(Unknown Source)
at com.google.android.gms.maps.internal.w.onTransact(SourceFile:66)
at android.os.Binder.transact(Binder.java:310)
at com.google.android.gms.maps.internal.IMapViewDelegate$zza$zza.onCreate(Unknown Source)
at com.google.android.gms.maps.MapView$zza.onCreate(Unknown Source)
at com.google.android.gms.dynamic.zza$3.zzb(Unknown Source)
at com.google.android.gms.dynamic.zza$1.zza(Unknown Source)
at com.google.android.gms.maps.MapView$zzb.zzzW(Unknown Source)
at com.google.android.gms.maps.MapView$zzb.zza(Unknown Source)
at com.google.android.gms.dynamic.zza.zza(Unknown Source)
at com.google.android.gms.dynamic.zza.onCreate(Unknown Source)
at com.google.android.gms.maps.MapView.onCreate(Unknown Source)
at com.test.maptest.TestFragment.onCreateView(TestFragment.java:343)
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.FragmentManagerImpl.moveToState(FragmentManager.java:1230)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:2042)
at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:165)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:543)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1170)
at android.app.Activity.performStart(Activity.java:5132)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2316)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
at android.app.ActivityThread.access$600(ActivityThread.java:162)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5403)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
依赖关系：
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:23.1.1'
compile 'com.google.android.gms:play-services:8.4.0'
compile 'com.mcxiaoke.volley:library:1.0.16'
compile 'com.android.support:support-v4:23.1.1'
compile 'com.android.support:recyclerview-v7:23.1.1'
compile 'com.google.android.gms:play-services-ads:8.4.0'
compile 'com.google.android.gms:play-services-identity:8.4.0'
compile 'com.google.android.gms:play-services-gcm:8.4.0'
}
问题是我只能在4.2.2的一部手机中使用，所有其他不同版本的手机都可以使用。显示地图，一切正常 任何人都可以帮我弄清楚发生了什么事吗？ 感谢。
编辑：这个特定的手机几个月前曾用过这个代码，所以问题可能是更新的Google Play服务和支持库吗？ 如果是这样，我们如何纠正它？
答案 0 :(得分：0)
因为你已经打过电话了
mapView.onCreate(savedInstanceState);
mapView.onResume();
这些方法不需要您调用。它们将由Android本身执行。正确地关注mapview教程。 ：）
也不要在onCreateView上做东西，做onViewCreated片段的方法。请发布您正在初始化的xml文件。