今天看到RotateAnimation的一个构造方法，final Animation rotateAnimation = new RotateAnimation(90f, 360f, Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF, 0f);

一下是官方文档的详细解释：

android.view.animation..RotateAnimation(float fromDegrees, float toDegrees, int pivotXType, float pivotXValue, int pivotYType, float pivotYValue)

Constructor to use when building a RotateAnimation from code

Parameters:

fromDegrees Rotation offset to apply at the start of the animation.动画开始时的角度。但是第一次点击开始动画，图片不会一开始就以90度的位置摆放，而是在开始动画的时候，才会从图片90度摆放的位置开发旋转。

toDegrees Rotation offset to apply at the end of the animation.动画结束时的角度。

pivotXType Specifies how pivotXValue should be interpreted. One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.设置类型。转动的点是以屏幕左上方开始还是别的方式。RELATIVE_TO_SELF，相对自己为标准；RELATIVE_TO_PARENT，相对父组件为标准；ABSOLUTE，表示绝对位置（那么对应的值应该是具体的坐标值，比如100到300，指绝对的屏幕像素单位）。

pivotXValue The X coordinate of the point about which the object is being rotated, specified as an absolute number where 0 is the left edge. This value can either be an absolute number if pivotXType is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.针对上面的类型具体的值。（0是左边缘，取值在0-1之间，1代表100%）

pivotYType Specifies how pivotYValue should be interpreted. One of Animation.ABSOLUTE, Animation.RELATIVE_TO_SELF, or Animation.RELATIVE_TO_PARENT.

pivotYValue The Y coordinate of the point about which the object is being rotated, specified as an absolute number where 0 is the top edge. This value can either be an absolute number if pivotYType is ABSOLUTE, or a percentage (where 1.0 is 100%) otherwise.

1. int firstPosition = postsListView.getFirstVisiblePosition(); 
2.         int visiblePosition = postsListView.getChildCount(); 
3.         for (int i = firstPosition; i < visiblePosition + firstPosition; i++) { 
4.             if (i == 0) {
   //指定了改变的具体Item，如果所有可视的Item都需要改变则不需要这个if判断 
5.                 View view = (View) postsListView.getChildAt(firstPosition); 
6.                 PostsTopicAdapterHolder topicHolder = (PostsTopicAdapterHolder) view.getTag(); 
7.                 ImageButton topicFavoriteBtn = topicHolder.getTopicFavoriteBtn(); 
8.                 if (topicModel.getIsFavor() == PostsApiConstant.TOPIC_UNFAVOR) { 
9.                     topicFavoriteBtn.setBackgroundResource(resource.getDrawableId("mc_forum_icon28")); 
10.                 } else { 
11.                     topicFavoriteBtn.setBackgroundResource(resource.getDrawableId("mc_forum_icon27")); 
12.                 } 
13.             } 
14.         }