原创文章，转载请注明：转载自Keegan小钢并标明原文链接：http://keeganlee.me/post/android/20151003微信订阅号：keeganlee_me写于2015-10-03
http://keeganlee.me/post/android/20151003
http://yongyu.itscoder.com/2016/12/25/animation_learning_note/
动画原理
http://blog.csdn.net/mr_liabill/article/details/49510485
