/**
     * @desc    平滑滾動(dòng)
     * @param    v        需要操控的視圖
     * @param    fromY    起始Y坐標(biāo)
     * @param    toY        終止Y坐標(biāo)
     * @param    fps        幀率
     * @param    durtion    動(dòng)畫(huà)完成時(shí)間（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    平滑滾動(dòng)線程，用于遞歸調(diào)用自己來(lái)實(shí)現(xiàn)某個(gè)視圖的平滑滾動(dòng)
     * */
    class SmoothScrollThread implements Runnable {   
        //需要操控的視圖
        private View v = null;     
        //原Y坐標(biāo)
        private int fromY = 0; 
        //目標(biāo)Y坐標(biāo)
        private int toY = 0;     
        //動(dòng)畫(huà)執(zhí)行時(shí)間（毫秒）
        private long durtion = 0;     
        //幀率
        private int fps = 60;      
        //間隔時(shí)間（毫秒），間隔時(shí)間 = 1000 / 幀率
        private int interval = 0;  
        //啟動(dòng)時(shí)間，-1 表示尚未啟動(dòng)
        private long startTime = -1;
        /減速插值器
        private DecelerateInterpolator decelerateInterpolator = null;

        /**
         * @desc    構(gòu)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() {
            //先判斷是否是第一次啟動(dòng)，是第一次啟動(dòng)就記錄下啟動(dòng)的時(shí)間戳，該值僅此一次賦值
            if (startTime == -1) {
                startTime = System.currentTimeMillis();
            }         
            //得到當(dāng)前這個(gè)瞬間的時(shí)間戳
            long currentTime = System.currentTimeMillis();     
            //放大倍數(shù)，為了擴(kuò)大除法計(jì)算的浮點(diǎn)精度
            int enlargement = 1000;         
            //算出當(dāng)前這個(gè)瞬間運(yùn)行到整個(gè)動(dòng)畫(huà)時(shí)間的百分之多少
            float rate = (currentTime - startTime) * enlargement / durtion;          
            //這個(gè)比率不可能在 0 - 1 之間，放大了之后即是 0 - 1000 之間
            rate = Math.min(rate, 1000);          
            //將動(dòng)畫(huà)的進(jìn)度通過(guò)插值器得出響應(yīng)的比率，乘以起始與目標(biāo)坐標(biāo)得出當(dāng)前這個(gè)瞬間，視圖應(yīng)該滾動(dòng)的距離。
            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);
        }
    }