RecyclerView ViewPager java.lang.NullPointerException android.support.v7.widget.RecyclerView $ ItemAnimator $ ItemHolderInfo.left

Question

我正在使用ViewPager和Recyclerview,但是在创建时它崩溃了......

我正在使用Recyclerview.Adapter尝试AsyncListUtil,并且它工作正常.当我将片段移动到ViewPager时,它开始像这样崩溃.任何见解？

            FATAL EXCEPTION: main
            Process: com.dekanski.popularmovies, PID: 6554
            java.lang.NullPointerException: Attempt to read from field 'int android.support.v7.widget.RecyclerView$ItemAnimator$ItemHolderInfo.left' on a null object reference
             at android.support.v7.widget.SimpleItemAnimator.animateChange(SimpleItemAnimator.java:130)
             at android.support.v7.widget.RecyclerView.animateChange(RecyclerView.java:3062)
             at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2924)
             at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3071)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1627)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.support.design.widget.CoordinatorLayout.layoutChild(CoordinatorLayout.java:1037)
             at android.support.design.widget.CoordinatorLayout.onLayoutChild(CoordinatorLayout.java:747)
             at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:761)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
             at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
             at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
             at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
             at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
             at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
             at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
             at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
             at android.view.View.layout(View.java:15671)
             at android.view.ViewGroup.layout(ViewGroup.java:5038)
             at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2086)
             at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1843)
             at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
             at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
             at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
             at android.view.Choreographer.doCallbacks(Choreographer.java:580)
             at android.view.Choreographer.doFrame(Choreographer.java:550)
             at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
             at android.os.Handler.handleCallback(Handler.java:739)
             at android.os.Handler.dispatchMessage(Handler.java:95)
             at android.os.Looper.loop(Looper.java:135)
             at android.app.ActivityThread.main(ActivityThread.java:5254)
             at java.lang.reflect.Method.invoke(Native Method)
             at java.lang.reflect.Method.invoke(Method.java:372)
             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

我已经弄清楚了...我错过了包含app:layout_behavior="@string/appbar_scrolling_view_behavior"到 ViewPager 中，所以 CoordinatorLayout 不知道如何正确完成它的工作。