/**      * @desc    平滑滚动      * @param    v        需要操控的视图      * @param    fromY    起始Y坐标      * @param    toY        终止Y坐标      * @param    fps        帧率      * @param    durtion    动画完成时间（毫秒）         * */     private void smoothScroll(View v, int fromY, int toY, int fps, long durtion) {          smoothScrollThread = new SmoothScrollThread(v, fromY, toY, durtion, fps);         smoothScrollThread.run();     }     /**      * @desc    平滑滚动线程，用于递归调用自己来实现某个视图的平滑滚动      * */     class SmoothScrollThread implements Runnable {            //需要操控的视图         private View v = null;              //原Y坐标         private int fromY = 0;          //目标Y坐标         private int toY = 0;              //动画执行时间（毫秒）         private long durtion = 0;              //帧率         private int fps = 60;               //间隔时间（毫秒），间隔时间 = 1000 / 帧率         private int interval = 0;           //启动时间，-1 表示尚未启动         private long startTime = -1;         /减速插值器         private DecelerateInterpolator decelerateInterpolator = null;         /**          * @desc    构造方法，做好第一次配置          * */         public SmoothScrollThread(View v, int fromY, int toY, long durtion, int fps) {             this.v = v;             this.fromY = fromY;             this.toY = toY;             this.durtion = durtion;             this.fps = fps;             this.interval = 1000 / this.fps;                   decelerateInterpolator = new DecelerateInterpolator();         }         @Override         public void run() {             //先判断是否是第一次启动，是第一次启动就记录下启动的时间戳，该值仅此一次赋值             if (startTime == -1) {                 startTime = System.currentTimeMillis();             }                      //得到当前这个瞬间的时间戳             long currentTime = System.currentTimeMillis();                  //放大倍数，为了扩大除法计算的浮点精度             int enlargement = 1000;                      //算出当前这个瞬间运行到整个动画时间的百分之多少             float rate = (currentTime - startTime) * enlargement / durtion;                       //这个比率不可能在 0 - 1 之间，放大了之后即是 0 - 1000 之间             rate = Math.min(rate, 1000);                       //将动画的进度通过插值器得出响应的比率，乘以起始与目标坐标得出当前这个瞬间，视图应该滚动的距离。             int changeDistance = (int) ((fromY - toY) * decelerateInterpolator.getInterpolation(rate / enlargement));                        int currentY = fromY - changeDistance;                       v.scrollTo(0, currentY);                        if (currentY != toY) {                 postDelayed(this, this.interval);             } else {                 return;             }         }           public void stop() {             removeCallbacks(this);         }     }