public void rotate(View view) {
//      iv.setRotation(rotation)//繞著中心點平面選擇
//      ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(iv, "rotation", 0,360);
//      iv.setRotationX(rotationX)//繞著水平中心線旋轉
//      ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(iv, "rotationX", 0,200);
//      iv.setRotationY
 
(rotationY)//繞著豎直中心線旋轉
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(iv, "rotationY", 0,360);

        objectAnimator.setRepeatCount(ObjectAnimator.INFINITE);

        objectAnimator.setDuration(1000);

        objectAnimator.start();

    }