title: Cause for NullPointerException android.support.v7.widget.RecyclerView.onMeasure
body: <p>I am getting following Exception</p>
  
  <pre><code>01-27 11:15:15.756  18348-18348/com.example.pnimje.newswipelistview E/AndroidRuntime﹕ FATAL EXCEPTION: main
      java.lang.NullPointerException
              at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:1764)
              at android.view.View.measure(View.java:15848)
              at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
              at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
              at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
              at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:453)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
              at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
              at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
              at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
              at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5008)
              at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
              at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2189)
              at android.view.View.measure(View.java:15848)
              at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1905)
              at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1104)
              at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1284)
              at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
              at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481)
              at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
              at android.view.Choreographer.doCallbacks(Choreographer.java:562)
              at android.view.Choreographer.doFrame(Choreographer.java:532)
              at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
              at android.os.Handler.handleCallback(Handler.java:730)
              at android.os.Handler.dispatchMessage(Handler.java:92)
              at android.os.Looper.loop(Looper.java:137)
              at android.app.ActivityThread.main(ActivityThread.java:5103)
              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:737)
              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
              at dalvik.system.NativeStart.main(Native Method)
  </code></pre>
  
  <p>and RecyclerView.java:1764 is</p>
  
  <pre><code>    mLayout.onMeasure(mRecycler, mState, widthSpec, heightSpec);
  </code></pre>
  
  <p>Why is mLayout (LayoutManager) null?</p>