AnimatorProxy 中的 Nineoldandroids NullPointerException 与 Robolectric

Question

我正在测试的视图有动画，当我使用 Robolectric 进行测试时，它似乎出错了。动画是一个简单的幻灯片，使用 Nineoldandroids 以实现兼容性。在 Robolectric 之外一切正常，但是我的单元测试因空指针而崩溃：

10:34:35.419 [DEBUG] [TestEventLogger]     java.lang.NullPointerException
10:34:35.419 [DEBUG] [TestEventLogger]      at com.nineoldandroids.view.animation.AnimatorProxy.applyTransformation(AnimatorProxy.java:316)
10:34:35.419 [DEBUG] [TestEventLogger]      at android.view.animation.Animation.getTransformation(Animation.java:870)
10:34:35.420 [DEBUG] [TestEventLogger]      at org.robolectric.shadows.ShadowView$2.run(ShadowView.java:492)
10:34:35.420 [DEBUG] [TestEventLogger]      at org.robolectric.util.Scheduler.runOrQueueRunnable(Scheduler.java:218)
10:34:35.420 [DEBUG] [TestEventLogger]      at org.robolectric.util.Scheduler.postDelayed(Scheduler.java:73)
10:34:35.421 [DEBUG] [TestEventLogger]      at org.robolectric.shadows.ShadowChoreographer.postCallbackDelayed(ShadowChoreographer.java:44)
10:34:35.421 [DEBUG] [TestEventLogger]      at android.view.Choreographer.postCallbackDelayed(Choreographer.java)
10:34:35.427 [DEBUG] [TestEventLogger]      at org.robolectric.shadows.ShadowView.setAnimation(ShadowView.java:487)
10:34:35.429 [DEBUG] [TestEventLogger]      at android.view.View.setAnimation(View.java)
10:34:35.431 [DEBUG] [TestEventLogger]      at com.nineoldandroids.view.animation.AnimatorProxy.<init>(AnimatorProxy.java:66)
10:34:35.432 [DEBUG] [TestEventLogger]      at com.nineoldandroids.view.animation.AnimatorProxy.wrap(AnimatorProxy.java:38)
10:34:35.432 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.PreHoneycombCompat$14.get(PreHoneycombCompat.java:161)
10:34:35.432 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.PreHoneycombCompat$14.get(PreHoneycombCompat.java:153)
10:34:35.432 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.PropertyValuesHolder.setupSetterAndGetter(PropertyValuesHolder.java:510)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.ObjectAnimator.initAnimation(ObjectAnimator.java:410)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.ValueAnimator.setCurrentPlayTime(ValueAnimator.java:538)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:928)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:951)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.ObjectAnimator.start(ObjectAnimator.java:385)
10:34:35.433 [DEBUG] [TestEventLogger]      at com.nineoldandroids.animation.AnimatorSet.start(AnimatorSet.java:502)

如果我在我的代码中添加检查以仅将 Nineoldandroids 用于 API

View view = mView.get();

mView 是mView = new WeakReference<View>(view);

任何建议如何从测试用例而不是我的应用代码中理想地解决这个问题？

Answer 1

似乎正在发生的事情是，在AnimationProxy 完全初始化之前，UI/Main 循环器执行了为列表元素设置动画的 Nineoldandroid 动画。这可能是因为在 Robolectric 3 中更好地模拟了 Android 线程架构。

我通过调用解决了这个问题：

ShadowLooper.pauseMainLooper();

将此调用放在任何可以在 Nineoldandroids 中启动动画的方法之前。

更新：

这给我带来了更多的麻烦，而且上面的解决方法很烦人，要推广到执行动画的每一位代码，所以我分叉并修复了它，非常小的变化：

https://github.com/apinder/NineOldAndroids/commit/6d399685dc5b3932e3b806d4d7d2f27123e1ca36