Choreographer NullPointerException

问题

I've been working on an existing codebase for a while and from browsing our crash log service I've noticed an exception that happens pretty frequently, I am not able to reproduce this issue, nor do I have the context for the scenario to try and dig in, as this is a pretty big project it has become increasingly hard to find out the cause of this exception.

I have been searching online for similar issues and couldn't find any useful information. If anyone is familiar with this issue, your help would be greatly appreciated.

Stacktrace is as follows:

java.lang.NullPointerException
   at android.animation.PropertyValuesHolder.setupSetterAndGetter(PropertyValuesHolder.java:505)
   at android.animation.ObjectAnimator.initAnimation(ObjectAnimator.java:487)
   at android.animation.ValueAnimator.setCurrentPlayTime(ValueAnimator.java:517)
   at android.animation.ValueAnimator.start(ValueAnimator.java:936)
   at android.animation.ValueAnimator.start(ValueAnimator.java:946)
   at android.animation.ObjectAnimator.start(ObjectAnimator.java:465)
   at android.animation.AnimatorSet$1.onAnimationEnd(AnimatorSet.java:579)
   at android.animation.ValueAnimator.endAnimation(ValueAnimator.java:1056)
   at android.animation.ValueAnimator.access$400(ValueAnimator.java:50)
   at android.animation.ValueAnimator$AnimationHandler.doAnimationFrame(ValueAnimator.java:644)
   at android.animation.ValueAnimator$AnimationHandler.run(ValueAnimator.java:660)
   at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
   at android.view.Choreographer.doCallbacks(Choreographer.java:574)
   at android.view.Choreographer.doFrame(Choreographer.java:543)
   at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
   at android.os.Handler.handleCallback(Handler.java:733)
   at android.os.Handler.dispatchMessage(Handler.java:95)
   at android.os.Looper.loop(Looper.java:136)
   at android.app.ActivityThread.main(ActivityThread.java:5105)
   at java.lang.reflect.Method.invokeNative(Method.java)
   at java.lang.reflect.Method.invoke(Method.java:515)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
   at dalvik.system.NativeStart.main(NativeStart.java)

Cheers.

回答1:

The issue turned out to be an animation being invoked from a Handler using postDelayed(), which eventually resulted in attempting to animate a null View reference, since it wasn't cleared properly according to it's host lifecycle events.

回答2:

maybe you tagret is null, print log with animatorSet.getTarget() to see

回答3:

I also get this stack trace when I use : ObjectAnimator animator = ObjectAnimator.ofFloat(this, "scale", 1); .... animator.start()

run in android 4.0.X, but it's ok for higher version, you can also refer this guy's commit, though I don't how to fix, however this is the root cause definitely.

回答4:

I went through this exception now and find out that I was getting the instance of the View with animation from getActivity().findViewById. While being in a fragment I had to instantiate it from the rootview inflated containing the view.

I basically moved the view from the Activity to the Fragment layout, but didn't change the code. So the rootview.findViewById resolved my problem.

My stacktrace:

java.lang.NullPointerException
    at android.animation.PropertyValuesHolder.setupSetterAndGetter(PropertyValuesHolder.java:505)
    at android.animation.ObjectAnimator.initAnimation(ObjectAnimator.java:392)
    at android.animation.ValueAnimator.setCurrentPlayTime(ValueAnimator.java:495)
    at android.animation.ValueAnimator.start(ValueAnimator.java:913)
    at android.animation.ValueAnimator.start(ValueAnimator.java:923)
    at android.animation.ObjectAnimator.start(ObjectAnimator.java:370)
    at eu.davidea.passwordcloud.ui.ItemDetailFragment$3.onClick(ItemDetailFragment.java:162)
    at android.view.View.performClick(View.java:4084)
    at android.view.View$PerformClick.run(View.java:16966)
    at android.os.Handler.handleCallback(Handler.java:615)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:4745)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    at dalvik.system.NativeStart.main(Native Method)

回答5:

Trust me, I found the solution of this crash issue on 4.0.x devices.

The problem is when you use ObjectAnimator without 'start' and 'end' value, the api on 4.0.x devices can't find the 'start' value to implement.

For example, this will lead to crash on 4.0.x devices

int endRadiusValue = 10;
ObjectAnimator
        .ofFloat(roundedGradientDrawable, "cornerRadius", endRadiusValue)
        .setDuration(200)
        .start();

And this code work perfect on all api level devices

int startRadiusValue = 0;
int endRadiusValue = 10;
ObjectAnimator
        .ofFloat(roundedGradientDrawable, "cornerRadius", startRadiusValue, endRadiusValue)
        .setDuration(200)
        .start();

回答6:

The reason is the target view is null. ObjectAnimator ofFloat(Object target, ...).
This crash will only throw in 4x device.
There is no crash in another device

回答7:

I solve the problem by adding the animation to a animationSet just like this:

来源：https://stackoverflow.com/questions/24105843/choreographer-nullpointerexception

标签

android

nullpointerexception