<rotate xmlns:android="http://schemas.android.com/apk/res/android" android:duration="1500" android:fillAfter="true" android:fromDegrees="0" android:pivotX="50%" android:pivotY="50%" android:repeatMode="restart" android:repeatCount="infinite" android:toDegrees="360" > </rotate>
anim = AnimationUtils.loadAnimation(context, R.anim.rotating);
anim.setInterpolator(new LinearInterpolator());//匀速插值器 解决卡顿问题