android动画

/**
* 旋转方法
*/
public void moveImg(ImageView iv, boolean b) {
final float centerX = iv.getWidth() / 2.0f;
final float centerY = iv.getHeight() / 2.0f;
RotateAnimation rotateAnimation;
if (!b) {
rotateAnimation = new RotateAnimation(0, 90, centerX,
centerY);
} else {
rotateAnimation = new RotateAnimation(90, 0, centerX,
centerY);
}
rotateAnimation.setDuration(500);
rotateAnimation.setFillAfter(true);
iv.startAnimation(rotateAnimation);

}