android控件显示与隐藏的时候的动画效果

Animation animBottomOut = AnimationUtils.loadAnimation(NewsDetailActivity.this,
                R.anim.bottom_out);
animBottomOut.setDuration(240);

rlCommentBarLayout.setVisibility(View.GONE);

rlCommentBarLayout.startAnimation(animBottomOut);

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fromYDelta="0"
        android:toYDelta="100%"
        android:fillBefore="true"  />

</set>

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fillBefore="true"
        android:fromYDelta="100%"
        android:toYDelta="0" />

</set>