Android知识回顾之动画

Android的动画分成三种：view动画，帧动画，属性动画，严格上说帧动画也是属于view动画的。

view动画的四种变化对应着Animation的四个子类：TranslateAnimation（平移动画），ScaleAnimation（缩放动画），RotateAnimation（旋转动画），AlphaAnimation（透明度动画）。

帧动画是顺序播放一组预先定义好的图片，类似电影播放。

属性动画可以是对任意属性进行动画，在API11（Android3.0）才有.比较常用的几个动画类有ValueAnimator，ObjectAnimator和Animatorset,其中ObjectAnimator继承自ValueAnimator，AnimatorSet是动画集合，可以定义一组动画。属性动画提供监听器监听动画播放过程，主要有如下两个接口：AnimatorUpdateListener和Animator

  public static interface AnimatorListener {        /**         * <p>Notifies the start of the animation.</p>         *         * @param animation The started animation.         */        void onAnimationStart(Animator animation);        /**         * <p>Notifies the end of the animation. This callback is not invoked         * for animations with repeat count set to INFINITE.</p>         *         * @param animation The animation which reached its end.         */        void onAnimationEnd(Animator animation);        /**         * <p>Notifies the cancellation of the animation. This callback is not invoked         * for animations with repeat count set to INFINITE.</p>         *         * @param animation The animation which was canceled.         */        void onAnimationCancel(Animator animation);        /**         * <p>Notifies the repetition of the animation.</p>         *         * @param animation The animation which was repeated.         */        void onAnimationRepeat(Animator animation);    }
 public static interface AnimatorUpdateListener {        /**         * <p>Notifies the occurrence of another frame of the animation.</p>         *         * @param animation The animation which was repeated.         */        void onAnimationUpdate(ValueAnimator animation);    }