匀速不间断旋转动画

xml：

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="2000"
    android:fromDegrees="0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:repeatCount="infinite"
    android:repeatMode="restart"
    android:toDegrees="+359" >
</rotate>

代码：

mAnim = AnimationUtils.loadAnimation(this, R.anim.video_prepare_rotate);

LinearInterpolator lir = new LinearInterpolator();

mAnim.setInterpolator(lir);

mVideoPrepareImg = (ImageView) findViewById(R.id.img_video_prepare);

mVideoPrepareImg.startAnimation(mAnim);