隨機亂數Math.random() 與 更新UI加速度/減速度的公式

//先以亂數決定UI要更新幾次 
int luckyNum = (int)(16 + Math.random() * 20); //range為16~36



new Thread(new Runnable(){

    @Override
    public void run() { 
        int count = 1;
        while(count <= luckyNum){
            try{

                //[做一些更新的動作]

                if((count <= luckyNum/10) || (count >= (luckyNum-luckyNum/10))){
                    // 最頭與最尾速度慢
                    Thread.sleep(300);

                }else if(((luckyNum/10 < count) & (count <= (luckyNum*2)/10)) || (((luckyNum*5)/10 < count) & (count <= (luckyNum*6)/10))){
                    // 次頭與次尾速度中
                   Thread.sleep(150);

               }else{
                   // 中間速度最快
                  Thread.sleep(50);

               }

               count++;                            
               }catch(Exception e){
                   e.printStackTrace();
               }

          }

     }           

}).start();