渐变展示启动屏

//渐变展示启动屏
    AlphaAnimation aa = new AlphaAnimation(0.2f, 1.0f);
    aa.setDuration(2000);
    binding.getRoot().startAnimation(aa);
    aa.setAnimationListener(new Animation.AnimationListener() {
        @Override
         public void onAnimationEnd(Animation arg0) {
         //跳转写这里
         }
        @Override
        public void onAnimationRepeat(Animation animation) {}
        @Override
         public void onAnimationStart(Animation animation) {}
    });