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私のアプリでViewPagerを使用して、タブに3つのフラグメントを表示しています。以下のクラッシュが問題に任意の詳細なポインタなしのDevコンソールで報告されている致命的な例外：ViewPagerを使用しているときにnullPointerExceptionが発生しました
エラー：
Attempt to invoke virtual method 'android.os.Handler android.support.v4.app.FragmentHostCallback.getHandler()' on a null object reference
そして次は、クラッシュの詳細です -
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Handler android.support.v4.app.FragmentHostCallback.getHandler()' on a null object reference
at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1613)
at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:633)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1177)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1025)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1545)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:668)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:735)
at android.view.View.measure(View.java:18880)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
at android.view.View.measure(View.java:18880)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18880)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2650)
at android.view.View.measure(View.java:18880)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2104)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1220)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1456)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1111)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6017)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:224)
at android.app.ActivityThread.main(ActivityThread.java:5526)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
誰でも同様の問題に直面し、どのような可能性解決する？
ここにあなたのJavaコードを投稿してください。 – Ironman
あなたのコードを親切に投稿すると、FragmentManagerをどのように使用してこのスレッドをチェックしているかが問題になる可能性があります http://stackoverflow.com/questions/34332900/android-support-v4-app-fragmentmanagerpopbackstackimmediate-results-in-a- null –
ポストコード、別の提案は、このチュートリアルを使用することですhttp://www.androidhive.info/2015/09/android-material-design-working-with-tabs/ – Manny265