1.ObjectAnimator是ViewPropertyAnimator的父类

2.valueAnimator.getAnimatedFraction():返回当前动画完成百分比

3.getAnimatedValue()得到当前动画中某个属性的准确值

4.实例：

Bitmap bitmap1,bitmap2;

bitmap1=...;

bitmap2...;

//判断当前状态

boolean mIsHeads=true;

ImageView imageView=..;

imageView.setImageBitmap(bitmap);

//获取ObjectAnimator对象

ObjectAnimator objectAnimator=ObjectAnimator.ofFloat(imageView,"rotationY",0f,360f);

objectAnimator.setDuration(500);

objectAnimator.addUpdateListener(new AnimatorUpdateListener(){

@Override

public void onAnimationUpdate(ValueAnimator animation){

if(animation.getAnimatedFration()>=0.25f && mIsHeads){

imageView.setImageBitmap(bitmap2);

mIsHeads=!mIsHeads;

}

if(animation.getAnimatedFraction()>=0.75f && !mIsHeads){

imageView.setImageBitmap();

mIsHeads=!mIsHeads;

}

}

});