占满整个屏幕，且实现缩放动画

<pre name="code" class="html"><set xmlns:android="http://schemas.android.com/apk/res/android">

<scale
android:interpolator= "@android:anim/decelerate_interpolator"
android:fromXScale="1.0"
android:toXScale="1.5"
android:fromYScale="1.0"
android:toYScale="1.5"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="0"
android:duration="4000"
android:repeatCount="1"
android:repeatMode="reverse"  />

</set>