SunsetFragment.java 文件源码

private void startAnimation() {
    float sunYStart = mSunView.getTop();
    float sunYEnd = mSkyView.getHeight();

    ObjectAnimator heightAnimator = ObjectAnimator
            .ofFloat(mSunView, "y", sunYStart, sunYEnd)
            .setDuration(3000);
    heightAnimator.setInterpolator(new AccelerateInterpolator());

    ObjectAnimator sunsetSkyAnimator = ObjectAnimator
            .ofInt(mSkyView, "backgroundColor", mBlueSkyColor, mSunsetSkyColor)
            .setDuration(3000);
    sunsetSkyAnimator.setEvaluator(new ArgbEvaluator());

    ObjectAnimator nightSkyAnimator = ObjectAnimator
            .ofInt(mSkyView, "backgroundColor", mSunsetSkyColor, mNightSkyColor)
            .setDuration(1500);
    nightSkyAnimator.setEvaluator(new ArgbEvaluator());

    AnimatorSet animatorSet = new AnimatorSet();
    animatorSet
            .play(heightAnimator)
            .with(sunsetSkyAnimator)
            .before(nightSkyAnimator);
    animatorSet.start();
}