CODEWITHSUNDEEP
androidnullpointerexceptionandroid-5.0-lollipopandroid-4.2-jelly-beanfindviewbyid
William Smith
William Smith

Reputation: 136

FindViewById / Butterknife.findById throwing NullPointerException only on API < 23

I am getting an NPE when I attempt to assign a LinearLayout variable during onCreate in a fragment. This error only happens in API versions < 23 (I have not tried them all, but have tried 19 and 16 and they crash on startup). On 23+ everything works perfectly and I am not sure why.

Code in question: 

public void reset() {
        layoutHolder = ButterKnife.findById(view, R.id.layoutHolder);
        //I get the same error using (LinearLayout) view.findViewById(...)
        if (layoutHolder.getChildCount() > 0) {
            layoutHolder.removeAllViews();
            layouts.clear();
            sections.clear();
            addSectionToLayout(createSection(1));
        }
}

view is initialized in the fragment's onCreate 

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        view = inflater.inflate(R.layout.fragment_log, container, false);
        //Omitted for brevity
        Butterknife.bind(this, view);
        return view;
    }

Error/stracktrace 

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.omitted, PID: 2236
java.lang.NullPointerException
 at butterknife.ButterKnife.findById(ButterKnife.java:343)
 at com.omitted.LogFragment.reset(LogFragment.java:156)
 at com.omitted.LogPresenter.reset(LogPresenter.java:35)
 at com.omitted.CalculatorModel.doReset(CalculatorModel.java:251)
 at com.omitted.CalculatorPresenter.onResetClicked(CalculatorPresenter.java:107)
 at com.omitted.CalculatorFragment.reset(CalculatorFragment.java:130)
 at com.omitted.CalculatorFragment.onCreateView(CalculatorFragment.java:97)
 at android.support.v4.app.Fragment.performCreateView(Fragment.java:1974)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
 at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:742)
 at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
 at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
 at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1916)
 at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1113)
 at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1295)
 at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
 at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
 at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
 at android.view.Choreographer.doCallbacks(Choreographer.java:574)
 at android.view.Choreographer.doFrame(Choreographer.java:544)
 at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
 at android.os.Handler.handleCallback(Handler.java:733)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:136)
 t android.app.ActivityThE/AndroidRuntime: FATAL EXCEPTION: main
 ess: com.omitted, PID: 2236
 .lang.NullPointerException
 at butterknife.ButterKnife.findById(ButterKnife.java:343)
 at com.omitted.LogFragment.reset(LogFragment.java:156)
 at com.omitted.LogPresenter.reset(LogPresenter.java:35)
 at com.omitted.CalculatorModel.doReset(CalculatorModel.java:251)
 at com.omitted.CalculatorPresenter.onResetClicked(CalculatorPresenter.java:107)
 at com.omitted.CalculatorFragment.reset(CalculatorFragment.java:130)
 at com.omitted.CalculatorFragment.onCreateView(CalculatorFragment.java:97)
 at android.support.v4.app.Fragment.performCreateView(Fragment.java:1974)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1252)
 at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:742)
 at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
 at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
 at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 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:16497)
 at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
 at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
 at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
 at android.view.View.measure(View.java:16497)
 at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1916)
 at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1113)
 at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1295)
 at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
 at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
 at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
 at android.view.Choreographer.doCallbacks(Choreographer.java:574)
 at android.view.Choreographer.doFrame(Choreographer.java:544)
 at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
 at android.os.Handler.handleCallback(Handler.java:733)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:136)
 at android.app.ActivityTh

I cannot seem to figure this out. Has anyone run into this problem before? Is the fragment lifecycle different on API<23 or something?

Any input is appreciated, thanks.

Upvotes: 0

Views: 616

Answers (1)

A.Grz
A.Grz

Reputation: 448

Did you use ButterKnife.bind(this, view) ?

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_log, container, false);
        ButterKnife.bind(this, view);
        // TODO Use fields...
        return view;
}

Upvotes: 1

Related Questions