在onCreateView android视图是null

我写了一个自定义视图，用于在24小时的垂直滚动时间轴中显示事件。

在膨胀这个视图的片段的onCreateView方法中，我膨胀视图，然后尝试设置视图公开的回调。 但是，当我试图在自定义视图上设置属性时（即自定义视图为空），我得到一个空引用异常。

这是我的布局（我的自定义DayView约束布局内）：

<?xml version="1.0" encoding="utf-8"?> <layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools"> <android.support.constraint.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".application.home.HomeActivity"> <com.condecosoftware.core.dayview.DayView android:id="@+id/dayView" android:layout_width="match_parent" android:layout_height="match_parent" app:timeColumnWidth="52dp" app:timeColumnPadding="16dp" app:hourHeight="96dp" app:textSize="14sp" app:eventNameTextSize="18sp" app:hourSeparatorHeight="1dp" app:timeTextColor="@color/slateGrey" app:timeColumnBGColor="@color/white_2" app:hourSeparatorColor="@color/white_2" app:nowLineColor="@color/lipstick" app:eventColumnBGColor="@android:color/white" app:eventBGColor="@color/brightSkyBlue" app:eventCornerRadius="3.8dp" app:eventTextColor="@android:color/white"/> </android.support.constraint.ConstraintLayout> </layout> 

现在，我应该注意的是，视图是膨胀和正确显示（如果我删除onCreateView中的回调的任务）。

这是导致NPE的代码（bizzarly，Kotlin不认为我试图访问的变量可以是空的（我不需要做安全的转换或任何东西来得到它））：

 @SuppressLint("MissingSuperCall") override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? { val viewBinding = FragmentBookingsTodayBinding.inflate(inflater ?: LayoutInflater.from(context)) // Setup day view listeners viewBinding.dayView.eventClickListener = this viewBinding.dayView.eventLongPressListener = this viewBinding.dayView.dayViewCallbacks = this this.viewBinding = viewBinding return viewBinding.root } 

我意识到我压制了这个方法的超级调用，但正如你所看到的，我正在返回在底部的视图绑定根，所以没关系。

有没有人有任何想法？

编辑（堆栈跟踪）：

 FATAL EXCEPTION: main Process: com.condecosoftware.roombooking.develop, PID: 3949 java.lang.NullPointerException: Attempt to invoke virtual method 'void com.condecosoftware.core.dayview.DayView.setEventClickListener(com.condecosoftware.core.dayview.DayView$EventClickListener)' on a null object reference at com.condecosoftware.roombooking.application.home.FragmentBookingsToday.onCreateView(FragmentBookingsToday.kt:53) at android.support.v4.app.Fragment.performCreateView(Fragment.java:2354) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1419) at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1809) at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:799) at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580) at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367) at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322) at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2199) at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:651) at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:167) at android.support.v4.view.ViewPager.populate(ViewPager.java:1236) at android.support.v4.view.ViewPager.populate(ViewPager.java:1084) at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1614) at android.view.View.measure(View.java:22002) at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1028) at android.view.View.measure(View.java:22002) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6580) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139) at android.view.View.measure(View.java:22002) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6580) 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:22002) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6580) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.view.View.measure(View.java:22002) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6580) 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:22002) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6580) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at com.android.internal.policy.DecorView.onMeasure(DecorView.java:721) at android.view.View.measure(View.java:22002) at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2410) at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1498) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1751) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1386) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6733) 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) at android.os.Handler.dispatchMessage(Handler.java:98) at android.os.Looper.loop(Looper.java:164) 10-21 14:05:30.514 3949-3949/com.condecosoftware.roombooking.develop E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:6541) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)