ViewPager上的ObjectAnimator导致IndexOutOfBound异常

Question

我正在使用ObjectAnimator为viewPager设置动画。 viewpager嵌套在RecyclerView中。如果在objectAnimator动画期间滚动，则会抛出IndexOutOfBound异常。这是代码段：

ObjectAnimator objectAnimator = ObjectAnimator
    .ofFloat(new PagerHintMovement(-10, viewPager), "progress", -1f, 1f);

objectAnimator.setInterpolator(new AccelerateInterpolator());
objectAnimator.setDuration(1500);
objectAnimator.setRepeatCount(1);
objectAnimator.setRepeatMode(ValueAnimator.REVERSE);
objectAnimator.addListener(new Animator.AnimatorListener() {
  @Override
  public void onAnimationStart(Animator animation) {
    Log.i(TAG, "Animation: Starting fake drag on view pager.");
    viewPager.beginFakeDrag();
  }

  @Override
  public void onAnimationEnd(Animator animation) {
    Log.i(TAG, "Animation: Ending fake drag on view pager.");
    viewPager.endFakeDrag();
    viewPager.setCurrentItem(viewPager.getCurrentItem());
  }

  @Override
  public void onAnimationCancel(Animator animation) {
    viewPager.setCurrentItem(viewPager.getCurrentItem());
  }

  @Override
  public void onAnimationRepeat(Animator animation) {

    if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR2) {
      if (animation.getInterpolator() instanceof AccelerateInterpolator) {
        animation.setInterpolator(new DecelerateInterpolator());
      } else {
        animation.setInterpolator(new AccelerateInterpolator());
      }
    }
  }
});
objectAnimator.setStartDelay(1000);
objectAnimator.start();

这是PagerMovement类。调用setProgress时会引发异常。 viewPager.fakeDragBy（目标*进度）导致IndexOutOfBound异常。

class PagerHintMovement {

float goal;
float progress;
ViewPager viewPager;

PagerHintMovement(float goal, ViewPager viewPager) {
  this.goal = goal;
  this.viewPager = viewPager;
}

public float getProgress() {
  return progress;
}

public void setProgress(float progress) {
  this.progress = progress;

  if (viewPager.isFakeDragging()) {
    Log.i("GalleryViewPagerAdapter",
        "Animation: Updating fake drag with value=" + goal * progress + "px");
    viewPager.fakeDragBy(goal * progress);
  }
}

}