var slide = new Slide({
        id:'grid-body',//元素ID
        onceHeight:43,//每行高度
        onceTime:500,//滑动一次用时毫秒 
        wait:1500//滑动后停顿毫秒
    });
    slide.start();

function Slide(options){
    this.element = document.getElementById(options.id); //元素
    this.onceHeight = options.onceHeight || 40;//滚动距离
    this.onceTime = options.onceTime || 200;//滚动一次需要的时间
    this.wait = options.wait || 1000;//等待时长（滚动一次后多久滚动下一次 单位：毫秒）
    this.frame = 1;//帧数
    this.frequency = this.onceTime / (this.onceHeight / this.frame);
    this.waitPoint = this.onceTime / this.frequency;
    this.coming = this.waitPoint + this.wait / this.frequency;
    this.prevFrame = this.element.scrollHeight / (this.onceTime / this.frequency);
    this.start = function(){
        let _this=this, j=this.waitPoint, isPrev=false;
        setInterval(function(){
            if(isPrev){//滚回顶部
                _this.element.scrollTop -= _this.prevFrame; 
                //判断是否滚动到顶部；
                if(_this.element.scrollTop <= 0){
                    //开始往下滑动
                    isPrev = false;
                    //准备等待
                    j = _this.waitPoint;
                }
            }else{
                j++;
                //等待结束
                if(j >= _this.coming){
                    //准备滑动
                    j = 0;
                    //判断是否滚动到底部；
                    if(_this.element.scrollTop + _this.element.clientHeight >= _this.element.scrollHeight){
                        //开始往上滑动
                        isPrev = true;return;
                    }
                }
                //等待……
                if(j >= _this.waitPoint)return;
                //设置滚动条到顶部距离
                _this.element.scrollTop += _this.frame; 
            }
        },this.frequency);
    }
}