js 实时监听滚动条状态 判断滚动条位置

  var scrollFunc = function (e) { 

           e = e || window.event; 

            var t = document.documentElement.scrollTop || document.body.scrollTop; //变量t就是滚动条滚动
             if (t <=100) {
                $(".top-header").attr('style','background:transport');

            }else{
                $(".top-header").attr('style','background:#47467e');
            } 

        /*     console.log(t); */
          /*  if (e.wheelDelta) { //第一步：先判断浏览器IE，谷歌滑轮事件   
            if (e.wheelDelta > 0) { //当滑轮向上滚动时
             console.log("滑轮向上滚动");
            }
            if (e.wheelDelta < 0) { //当滑轮向下滚动时
             console.log("滑轮向下滚动");
            }
           } else if (e.detail) { //Firefox滑轮事件
            if (e.detail> 0) { //当滑轮向上滚动时
             console.log("滑轮向上滚动");
            }
            if (e.detail< 0) { //当滑轮向下滚动时
             console.log("滑轮向下滚动");
            }
           } */
          }
          

        //给页面绑定滑轮滚动事件
        if (document.addEventListener) { //firefox
            document.addEventListener('DOMMouseScroll', scrollFunc, false);
        }
        //滚动滑轮触发scrollFunc方法 //ie 谷歌
        window.onmousewheel = document.onmousewheel = scrollFunc;