我在使用RecyclerView时遇到问题，确切地说，该问题仅在扩展名为Fragment的类的onCreateView中发生。
public class LiveAction extends Fragment {
...
private List<Live> displayList = new ArrayList<>();
private RecyclerView recyclerView;
private LiveAdapter lAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View inflatedView = inflater.inflate(R.layout.content_main, container, false);
...
lAdapter = new LiveAdapter(displayList);
//here the problem:
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(lAdapter);
我已经尝试将getApplicationContext（）替换为getContext（），getActivity（）。 GetApplicationContext（）和其他方法，最多只能得到另一个错误（例如，使用getActivity（）。GetApplicationContext（））：“方法调用get'getApplicationContext'可能会产生'java.lang.NullPointerException'...”。 我在哪里错了？
Logicat错误（在S7 Edge上测试）
06-21 22:05:46.015 23990-23990/name.app D/AndroidRuntime: Shutting down VM
06-21 22:05:46.021 23990-23990/name.app E/AndroidRuntime: FATAL EXCEPTION: main
Process: name.app, PID: 23990
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setLayoutManager(android.support.v7.widget.RecyclerView$LayoutManager)' on a null object reference
at name.app.LiveAction.onCreateView(LiveAction.java:83)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2346)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1428)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1759)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1827)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:797)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2596)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2383)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2338)
at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2215)
at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:649)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:145)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1238)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1086)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1616)
at android.view.View.measure(View.java:23297)
at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1212)
at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1552)
at android.view.View.measure(View.java:23297)
at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1059)
at android.view.View.measure(View.java:23297)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:141)
at android.view.View.measure(View.java:23297)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
at android.view.View.measure(View.java:23297)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure(View.java:23297)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
at android.view.View.measure(View.java:23297)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6928)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at com.android.internal.policy.DecorView.onMeasure(DecorView.java:899)
at android.view.View.measure(View.java:23297)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2844)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1874)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2129)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1743)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7780)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:911)
at android.view.Choreographer.doCallbacks(Choreographer.java:723)
at android.view.Choreographer.doFrame(Choreographer.java:658)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:897)
at android.os.Handler.handleCallback(Handler.java:789)
06-21 22:05:46.022 23990-23990/name.app E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6944)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)